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Catalyst - Science topic

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I am trying to prepare a Ni-based catalyst(Ni/Ce2O3) by co-precipitation method. I was wondering what is the best precipitation agent and PH.
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Azita Etminan You don't mention the concentration of Ni you require in the final material but the usual route to produce catalysts of this nature with Ni in the 1 - 5 wt% typically is by impregnation of the base material (e.g. Ni/SiO2, Ni/CaCO3 etc) and then subsequent reduction. Simple precipitation of Ni salts with base produces Ni(OH)2 which will calcine to NiO and not Ni.
The preferred route would need a knowledge of the pore volume of the base (do you really mean Ce2O3 and not CeO2?). This knowledge can be obtained by simple titration of a known amount of the dry material or via porosimetry. A solution of the appropriate Ni precursor (nitrate would always be preferred over chloride) would be used to just saturate the pores and produce an x wt% Ni in the final powder. Reduction would then take place (in the dry with H2; in the wet my preferred reductant would be 5 or 10% hydrazine hydrate as the only products are water and N2). This would then produce Ni in the required concentration on the substrate. A further drying process would be needed for wet reduction. I'd avoid borohydride reduction as this always leaves intractable B in the matrix.
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I am looking for examples where markets have developed mainly through public procurement as a consumer rather than via policy making.
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Petrobras, a major state-owned oil company in Brazil, has indeed played a significant role as a catalyst in developing various markets, both within Brazil and internationally, suco as::
1. Offshore Oil Exploration and Production: One of the most notable areas where Petrobras has been a catalyst is in deep-water and ultra-deep-water oil exploration and production. The company's investments and technological advancements in this field have not only bolstered Brazil's oil industry but have also led to the development of a specialized market for deep-sea exploration technology and services.
2. Local Content Development: Petrobras has often been involved in initiatives that require suppliers to use a certain percentage of local content. This has helped develop local industries in Brazil, particularly in the oil and gas supply chain, fostering the growth of local businesses, manufacturing, and services.
3. Renewable Energy Sector: Although primarily an oil company, Petrobras has also ventured into renewable energy sources, such as biofuels, wind, and solar energy. These ventures have helped stimulate the renewable energy market in Brazil, encouraging innovation and investment in these areas.
4. Shipbuilding Industry: In an effort to renew its fleet, Petrobras initiated programs that required new ships to be built in Brazil, which led to a revival of the Brazilian shipbuilding industry.
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can we use the ANN-GA optimisation algorithm to optimize chemical reactions?
if yes minimum how much data is required?
currently, I am working with a catalytic process I want to optimize the performance of the catalyst corresponding to the process parameters. previous research papers used from 32 to 48 process data. is it enough to predict and optimize the process parameters?
Please help me reg..this
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You need to train a regression neural network with your experimental data. Then keep the trained neural network in your workspace. You can use this trained model as an objective function simply by using the function handle. Say the name of the trained model is 'trainednet'. The objective function can then be defined obj_func = predict(trainednet,x). You can use it as objective function by calling @obj_func
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Hi everyone,
If I want to doping Co in NiFe2O4 with 3 wt%,
For example, Fe(NO3)3.9H2O (1 g), Ni(NO3)2.6H2O (1 g) and Co(NO3)2·6H2O (3wt%). So, 2 g x 3/100 = 0.06 g of Co(NO3)2·6H2O. The result will be (0.97 g for Fe(NO3)3.9H2O and Ni(NO3)2.6H2O) and (0.06 for Co(NO3)2·6H2O), With the appropriate solvent.
Please, Let me know if I’m wrong and correct me.
thank you in advance.
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Ghada Aljaber Thank you for your question. This is relatively simple to answer with a grasp of chemistry but does need some care with the calculations.
So, you want to end with 3wt% Co in NiFe2O4 – that is, 0.03 g Co plus 0.97 g NiFe2O4 for a gram of final material. OK, so how do we get there? Consider NiFe2O4 as an equal ‘mix’ of NiO plus Fe2O3. Let’s consider getting to a gram of the doped material as then if we want to make more then we simply have to multiply the amounts of the starting [precursors by the appropriate factor.
The MW of the precursors and the decomposition route are key:
• Fe(NO3)3.9H2O MW 403.999 g/mol gives rise to Fe2O3 (MW 159.6882 g/mol) on decomposition. We note that we’d need 2 moles of the nonahydrate to give rise to 1 mole of the oxide
• Ni(NO3)2.6H2O MW 290.79 g/mol gives rise to NiO (MW 74.6928 g/mol) on decomposition
• Co(NO3)2·6H2O MW 291.03 g/mol gives rise to CoO (MW 74.93 g/mol) on decomposition. You’re specifying Co (atomic mass 58.93) not CoO
• NiFe2O4 MW 234.381 g/mol. In 1 g of this material, we’d have 159.6882/234.381 g of Fe2O3 and 74.6928/234.381 g of NiO. For 0.97 g of NiFe2O4 we’d need 0.97*(159.6882/234.381) g of Fe2O3 and 0.97*(74.6928/234.381) g of NiO
Let’s start with the dopant (Co) first. To get 0.03 g of cobalt would require 0.03*(74.93/58.93) g of CoO which would be produced from a multiplier of (291.03/74.93) g of the hexanitrate. Thus, we’d need 0.03*(74.93/58.93)*(291.03/74.93) g of the precursor hexanitrate to lead to 0.03 g of Co
Now, the iron nonahydrate. (2 X 403.999) of this gives rise to 159.6882 g of Fe2O3, so we need (2 X 403.999)/159.6882 g of the nonahydrate to give rise to 1 g Fe2O3. We actually require 0.97*(159.6882/234.381) g of Fe2O3 equivalent in the final product. So our starting nonahydrate would be 0.97*(159.6882/234.381)*[(2*403.999)/159.6882] g of this precursor
By a similar argument, for the NiO equivalent, then to get 0.97*(74.6928/234.381) g of NiO requires a multiplier of (290.79/74.6928) of the hexahydrate. That is (290.79/74.6928)*0.97*(74.6928/234.381) of the nickel nitrate hexahydrate for a gram of the final NiFe2O4.
You need to check my math and that I haven’t made a typo (or several typos) and also that I have the molecular masses of the compounds correct. I’ll leave you to multiply out the final values and check that they’ll make 1 g of final material. For larger amounts you can multiply by the appropriate factor, as I said earlier.
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For HER reaction for a halide based photocatalyst I get the different results of hydrogen after all repeated result even experimental conditions are same.
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You definitely have a leak of air into your set up not necessarily in GC. As a result, oxygen reduction reaction compete with proton reduction. Do a control experiment with everything in your system, but without a catalyst. You should not see any O2/N2 peaks.
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How is tristyrylphenol is produced and which catalyst is used industrially?
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Jürgen Wintner Thank you very much!
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CALL FOR CHAPTERS
The Evolution of Artificial Intelligence in Higher Education: Challenges, Risks, and Ethical Considerations
Editors: Miltiadis D. Lytras, Afnan Alkhaldi, Sawsan Malik
Publisher: Emerald Publishing
Emerald Studies in Active and Transformative Learning in Higher Education,
Scope, Strategy and Topics Covered
This volume serves as a reference edition for the challenges, opportunities, risks and adoption of Artificial Intelligence in all aspects of Higher Education. With emphasis on the diverse facets of the AI, namely procedural, methodological, technical and ethical this book covers in a holistic way the evolution of the AI in Higher Education. Case Studies, Lessons Learnt and Research and Development Projects of the utilization of AI in Higher Education are also covered promoting the debate on the future of AI in Higher Education
The aim of this volume is to cover the excessive needs of faculty, administrators, policy makers and stakeholders in the Higher Education industry on timely and trusted knowledge on the impact of the Artificial Intelligence in the Higher Education Institutions and Ecosystem. Our volume is one of the first efforts to accommodate in a single volume the diverse aspects of the phenomenon with a constructive, progressive approach aiming to investigate the positive footprint of the application of the AI in the HE.
The selected structure of our volume is also representative of our own unique strategy. The following are the sections that will host the chapters:
  • Section 1. AI as a Catalyst for the Higher Education Ecosystem and Value proposition
  • Section 2. Threats, Opportunities, Challenges and Risks on the Adoption of AI in HE
  • Section 3. A new era of AI-enabled instructional and learning strategic, engagement and interactivity in Higher Education
  • Section 4. Enrichment of Learning Experience and Social Impact through AI in Higher Education
  • Section 5. Administrative and Ethical issues: Managing AI as a core function of Higher Education Process
  • Section 6. ChatGPT, Generative AI, OpenAI special focus: Hype, Functional and Strategic Perspectives on its use on HE institutions.
In this book, there is an integrated coverage of significant items in the relevant agenda providing a unique value proposition for the relevant area. The following list is indicative and not exhaustive.
  • AI as a catalyst for the Higher Education Ecosystem
  • AI as an enabler of Digital Transformation in Higher Education: Threats, Promises, implementation strategies and intended impact
  • AI as an innovative approach to next generation instructional methods and learning strategies?
  • The context of Disrupting Education: How Artificial Intelligence revolutionizes the higher education landscape
  • Deployment of Artificial Intelligence in the value chain of the Higher Education.
  • The role of the AI in the implementation of Active Learning in STEAM courses in Higher Education
  • Promoting interactivity, inclusion and engagement in Higher Education
  • Enhancing interactive learning experiences and student engagement through ChatGPT, Generative AI, OpenAI
  • The role of ChatGPT, Generative AI, OpenAI in Revolutionizing Lifelong Learning in Higher Education
  • Innovative methodological frameworks for the integration of AI in Higher Education
  • Ethical issues on the use of AI in Higher Education
  • Using ChatGPT, Generative and Open AI in teaching HE courses
  • Enhanced Decision Making in Higher Education Administration with Artificial Intelligence
  • Technology Literacy and adoption of AI and ChatGPT, Generative AI, OpenAI in Higher Education
  • Adopting ChatGPT, Generative AI, OpenAI for designing training modules for HE Courses
  • ChatGPT, Generative AI, OpenAI in Higher Education: Hype or a new pillar of developing next generation skills to students
This edition can serve as a reference edition as well as a teaching book for postgraduate studies on the relevant domain.
Deadlines
  • 25th November, 2023; Submission of Abstracts (Use the Emerald Template attached)
  • 15th February, 2024, Submission of Full Chapters
  • 15th March, 2024, Final chapters due (review comments incorporated)
  • November 2024, Publication
Specifications:
  • There is no charge for contributing authors
  • Emerald Publishing is offering complementary ebook for all contributors
  • The volume is Scopus Indexed (typically 3-5 months after publication)
Editors (send your abstract to any of them)
Miltiadis D. Lytras, Effat University, Saudi Arabia, miltiadis.lytras@gmail.com
Afnan Alkhaldi, Arab Open University, Kuwait Branch, Kuwait, aalkhaldi@aou.edu.kw
Sawsan Malik, Arab Open University, Kuwait Branch, Kuwait, smalik@aou.edu.kw
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I clicked on the LINK in the above Call for Chapters. Here is a copy-and-paste of the template, which will give you an idea of the required elements; however, it looks like you will have to have the original form to submit.
Also, the original version shows yellow highlighting for most of the bold face rubrics, as well as some of the explanatory regular font guidelines.
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Best wishes,
Nancy Ann Watanabe
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The photodegradation experiment materials included RhB, catalyst (catalyst does not include carbon or carbon compounds), crystallizing dish, and magnetic stirrer. After 2 hours of irradiation, the RhB is decolorized by the catalyst, and the RhB dye color changes from pink to transparent (do not observe any pink on the catalyst). The mixture included Catalyst and RhB centrifuged for 10 min to remove the catalyst. The irradiated RhB and not irradiated RhB were filled into glass vials for TOC analysis. However, the results could not be accepted. The not irradiated RhB TOC concentration is large than the TOC of irradiated RhB. Wondering if any professor could give suggestions or comments.
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Hello Dr. Henrik Rasmus Andersen,
thanks for your reply. The experiments were finished in June. Currently, I don't have any questions. The reason behind the issue was the evaporation of some water in the organic dye. During three hours, the experiment was performed under light, the light makes heat. As a result, the final solution lost a significant amount of water, increasing the final TOC. Sorry for the delayed response.
Best regards.
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What I am doing recently is to load bismuth oxybromide on foam nickel. The hydrothermal method is adopted. After hydrothermal treatment, foam nickel is dried in an 80 degree oven to degrade rhodamine. During the degradation process, catalyst particles will fall off. How can I make the catalyst load more firmly.
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In my opinion, the poor fixation of the BiOBr photocatalyst to the nickel substrate is due to two reasons: too weak adhesion of oxybromide to nickel (there are no functional groups capable to form chemical bonds between these components) and an excessively high difference in the thermal expansion coefficient of nickel and oxybromide. Therefore, three approaches could be tested (in order of their feasibility):
- deposit an intermediate buffer layer, for example, made of metallic bismuth, onto the surface of the nickel substrate, then apply BiOBr to it;
- distribute BiOBr particles in a binder that does not impair the functioning of the photocatalyst (for example, like magnesium cement or a porous photo stable polymer);
- chemically modify the nickel surface, for example, by treatment it in passivating media.
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JAS Google AI BARD LLM (Cut & Paste)
Is SPRT real? Can it be mass produced for a given purpose?
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SPRT, or Self-Propagating Room Temperature Synthesis, is a real process that has been demonstrated in laboratory settings. It is a method of manufacturing materials at room temperature by using a chemical reaction to generate heat. The heat then propagates through the material, causing it to synthesize.
SPRT has the potential to be mass-produced for a given purpose. However, there are still some challenges that need to be addressed before it can be commercialized. One challenge is that SPRT reactions can be difficult to control, and there is a risk of explosions. Another challenge is that SPRT reactions can produce harmful byproducts.
Researchers are working on addressing these challenges, and there has been significant progress in recent years. For example, researchers have developed new SPRT catalysts that make the reactions more controllable and less likely to explode. They have also developed methods for capturing and disposing of harmful byproducts.
It is likely that SPRT will be mass-produced for commercial purposes in the next few years. However, it is difficult to say exactly when this will happen, as it depends on the progress that is made in addressing the remaining challenges.
Here are some potential applications for mass-produced SPRT:
  • Manufacturing materials for batteries, solar cells, and other electronic devices
  • Producing catalysts for chemical reactions
  • Creating new materials for aerospace and automotive applications
  • Developing new medical implants and drug delivery systems
Overall, SPRT is a promising technology with the potential to revolutionize the way that materials are manufactured. However, there are still some challenges that need to be addressed before it can be commercialized.
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a spark of light perhaps....
JAS Claude.ai LLM (Summary, Cut & Paste)
define how to quantify, qualify and subjectify spirit based on the following: https://www.researchgate.net/post/Is\\_SPRT\\_real\\_Can\\_it\\_be\\_mass\\_produced\\_for\\_a\\_given\\_purpose
Claude can't visit links. Responses may contain hallucination.
JA
I do not have a definitive way to quantify, qualify or subjectify spirit, as it is an abstract concept. However, here are some perspectives on how one could approach analyzing spirit:
Quantify:
  • Measure frequency/intensity of spiritual experiences through surveys or self-reports
  • Assess engagement in spiritual practices like prayer, meditation, rituals
  • Look at neurological activity correlated with spiritual states using fMRI or EEG
Qualify:
  • Describe the nature and qualities of spiritual experiences through first-person accounts
  • Identify themes and patterns in spiritual experiences across traditions and cultures
  • Develop phenomenological descriptions of spiritual states of consciousness
Subjectify:
  • Examine the meaning and significance individuals ascribe to spiritual experiences
  • Analyze how spirituality is incorporated into personal identity and life narratives
  • Study the role of spirituality in cognitive frameworks, worldviews and belief systems
The researchgate post seems to be discussing SPRT (Spirit Possession Research Training) which involves training mediums. I do not have enough information to determine if SPRT can be mass produced for a specific purpose. Examining spirit possession phenomena requires an interdisciplinary approach including anthropological, psychological and neurological perspectives. More research would be needed to evaluate the viability of standardizing spiritual mediumship training. Overall, analyzing something as abstract as spirit requires combining objective measures with subjective perspectives and meaning.
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The organic pollutant I chose was diethyl phlatate using MIL-125 (Ti) catalyst and irradiated with a UV lamp, but the results I obtained with increasing time, the DEP concentration increased. What could be the factors that influence this?
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Very strange--please check your experimental setup and your analytical methods?
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Laboratory Research
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Thank you
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Researchers have used different range of log abs J, depending upon what criteria? I want to calculate tafel slope of my catalyst NiS, what range should i choose ? Here my polarisation curve.
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Dear Hamza Naeem , what I wrote is to explain how to build a Tafel plot, because what you show is a polarization curve. You should analyze your data as a Tafel plot based on what is described for HER.
Check this:
and this:
Regards!
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My sample is a catalyst based on metal oxide(NiO, Ce2O3) I want to do TEM test, I was wondering how to prepare the sample for the TEM test?
Thank you.
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If your sample is nano-powder, a small amount of your catalyst nano-powder sample ( one or two grains) is dispersed in ethanol (10 ml). Every step is taken very carefully to avoid the contamination. Place a droplet of the catalyst nano-powder suspension on the TEM grid using a glass dropper (cleaned and washed) then allow the ethanol to evaporate (minimum 24 hours). after completing this protocol sample grid insert the sample holder and insert the TEM.
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I tried to measure the EIS of my photocatalyst by using only a working electrode (my catalyst was dip dropped on FTO) and a counter electrode (Pt), but most of the times it showed a high impedance and every time l run it wasn't the same with the other trying.
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Using a two electrode setup, you may measure the impedance without a reference electrode. You'll need a stable reference electrode if you simply want to conduct your research on working electrodes. Reference electrode is required for electrochemical cell measurement accuracy and constant ground voltage.
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Hi all, I've read hundreds of articles on the use of TiO2 as a photocatalyst to degrade Methylene Blue from water. I have also conducted my own work on this particularly via the sol-gel route as well as nano powder slurries and nano powder immobilised in PVA crosslinked with PEG. I've replicated 10 or so methods from various papers, often with completely different results than they had. Actually with failures. The one thing I did not replicate, is when they specify they used a UVC (254nm) light, I did not. I always used an 11W UVA (385nm) light (replacing the bulb often for certainty. In trying to find what my error was, I switched to a UVC light and got the same results as the authors. I then removed the catalyst and also still got the same results, with a UVC light only. Indicating Methylene Blue was being degraded via Photolysis. My results always checked on a Thermo Helios Spectrophotometer with an absorbance peak of 664. My question is, are these research articles, none of whom described running a control without the catalyst, actually achieving photocatalysis in their lab reactors? Or are they being led to believe they've succeeded due to Photolysis? Why is no-one talking about removal of Methylene Blue via 254nm UVC light? My reactor is Quartz glass with the UVC light sitting externally and the reaction occurring under stirring. I have replicated it 8 times with the same results. When I switch to 385nm only, I get no removal of MB. When I install a TiO2 catalyst, I also get no changes. Clearly my catalysts are flawed but I've asked that in another question with no real answers so far.
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You are right and wrong in your research and questions. The decomposition of methylene blue can occur without a catalytic agent. All catalysts reduce the activation energy of a reaction and therefore speed up the reaction. Reviewers of some paid journals may pass up an article with no experience, that is, without a catalyst for their profit. I wrote about such citations in my post.
Titanium dioxide has a number of allotropic forms: anatase, rutile, mixtures of them and various catalysts. It is necessary to check their structure and particle size. The smaller the nanoparticle size, the better the catalyst.
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As GHSV, gas hourly space velocity is basically the ratio of volumes of feed gas at STP/hr to the volume of the reactor or catalyst. Can we report the GHSV based on mL*gr-1cat h−1 because it would be difficult to calculate the exact volume of a catalyst powder?
Thank you.
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Jorge Arce Castro Thank you. But I have a gas flow!
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We have gotten the negative value of a CdS-based composite catalyst. Is it correct for PCORR?
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Zeta potential is a parameter that can indicate the stability of a disperse system to aggregation of catalyst nanoparticles or sedimentation. It depends on the composition of the dispersed system, pH, electrolytes... If the dispersed system is stable, it will work well as a photocatalytic catalyst. For your disperse system, it is necessary to experimentally determine the zeta potential.
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Good evening everyone
I am working on green synthesis of selenium nanoparticles from leaf extract. The research article mentions that during selenium nanoparticle synthesis, ascorbic acid should be used as a catalyst. so why there is a need to use a catalyst?., and what is the best drying method for synthesized selenium nanoparticles?
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Hi Mohini Tayade,
A catalyst is a substance that can be characterized as homogeneous which is in the same phase as the reactants liquid or gas, and heterogeneous, or enzymatic that are not in the same phase as the reactants. When catalysts are added to a reaction, it increase the reaction rate without getting consumed in the process, in addition to accelerating a reaction by reducing the activation energy or changing the reaction mechanism, so, it prevents agglomeration when synthesizing the nanomaterial.
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  • BJH Adsorption cumulative volume of pores between 2.0000 nm and 300.0000 nm diameter: 0.067637 cm³/g
  • BJH Desorption cumulative volume of pores between 2.0000 nm and 300.0000 nm diameter: 0.113131 cm³/g
From the above data, which data should be added to the manuscript?
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Thank you!
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Using Pt based and iridium based catalysts for PEM electrolyzer is quite expensive and is a biggest challenge. But what're the other technical challanges encountered using such catalysts? What're the possible ways to bring down the cost as well the rest of challanges?
Looking for potential answers pls
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Dear Doctor
Go To
Current Challenges in Catalyst Development for PEM Water Electrolyzers Maximilian Bernt, Alexandra Hartig-Weiß, Mohammad Fathi Tovini, Hany A. El-Sayed, Carina Schramm, Jonas Schro¨ ter, Christian Gebauer , and Hubert A. Gasteiger
DOI: 10.1002/cite.201900101
"Conclusions
In this work, an overview of the current challenges in catalyst development for PEM-WEs is given. Due to the limited availability of iridium which is currently the only viable option as an oxygen evolution reaction (OER) catalyst, a reduction of the iridium loading from currently » 2 mgIr cm–2 to only » 0.05 mgIr cm–2, i.e., by a factor of 40 is required in order to enable a large-scale application of PEM-WEs. While the activity of current Ir-based catalysts would generally be sufficient to achieve the proposed target values for Ir loading at only minor performance losses (only 4 % increase of the cell energy consumption to produce 1 kg of H2), the development of catalyst structures with a much lower iridium packing density compared to current catalyst materials is absolutely required to realize homogeneous catalyst layers at very low Ir loadings. Several pathways to develop such high-structured catalysts (i.e., catalysts with a low iridium packing density) have been proposed in the literature. Here we show first results that demonstrate that for a high-structured catalyst a reduction of the Ir loading by a factor » 8 is possible, even with a slightly improved efficiency compared to a commercial Benchmark catalyst. With this new OER catalyst developed by Heraeus, the Ir-specific power density at an efficiency of 70%LHV (≡ 1.79 V) of » 0.05 gIr kW–1 can be achieved at > 3 A cm–2 with a 50 mm thick Nafion membrane. To make the development of new catalyst materials more efficient, activity and durability screening methods are required to allow a fast identification of promising materials. The rotating disk electrode (RDE) method which is commonly used to evaluate catalyst performance is shown to be suitable for a characterization of catalyst activity, while OER catalyst stability tests are affected by measurement artefacts and, hence, do not give meaningful information about catalyst lifetime. Consequently, accelerated stress tests (AST) on the membrane electrode assembly (MEA) level are required to evaluate catalyst stability at realistic operating conditions. A test protocol simulating an intermittent power supply by cycling between open circuit voltage (OCV) and operating potentials is presented as an example for such an AST. Here, the recurring transition between reducing and oxidizing conditions leads to the dissolution of Ir and the formation of a contact resistance between electrode and PTL resulting in a much higher degradation rate compared to a reference experiment without OCV periods. The information gained from this experiment helps to identify harmful operating conditions that need to be avoided in real PEM-WE systems."
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I am synthesizing P3HT by oxidative polymerization of 3-Hexylthiophene by using FeCl3 as catalyst. While going through the relevant literature, I came to know that polymerization has to be conducted in the inert atmosphere (N2 or Ar). But, I couldn't understand the exact reason for doing so. Can someone help me with this?
Any insights is much appreciated. Thank you!
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.FeCl3 is not oxidized by atmospheric oxygen. However, in your reaction it will act as a weak oxidizing agent at the double bonds to allow polymerization to occur. Without an inert gas, the oxidation of thiophene by atmospheric oxygen can proceed through sulfur, which will lead to a deterioration in the polymerization reaction.
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Pt has been remarkable Hydrogen Evolution Reaction electrocatalyst in Acid which perform good even in large scale electrolysers.
While there are plenty of engineered HER catalyst reports most of them fail at reasonably high currents and long term testing. I wonder if there is any catalyst with higher intrinsic activity than Pt?
Thanks
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Dear Aaditya
Then main important feature of Pt, by which makes it an ideal option, is the fact that Pt is a noble metal. For electrodeposition studies in acidic media, you have no concern about the possible dissolution of Pt. Therefore, you can focus on the mechanism of hydrogen evolution. I think you can also use other noble metals such as Pd, Ag, etc..
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Hi
I`m trying to synthesis zeolite catalyst and I need silica sol 25wt%
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Hello Mona,
You may buy it online. You may make an inquiry at Alfa Chemistry, they offer kinds of good-quality products.
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I am about to conduct a photocurrent analysis on my synthesized catalysts, but I have no idea about the appropriate potential that needs to be applied to obtain accurate photocurrent measurements.
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Hai Dear Atiyeh Karkhaneh Jafary, I hope this will help to you
The proper potential for photocurrent analysis depends on the type of catalysis and the materials involved. In general, the potential should be chosen so that the photoexcited electrons can be injected into the conduction band of the semiconductor, but not so high that they are immediately lost to recombination. The exact potential will need to be determined experimentally for each system.
For example, in the case of photoelectrochemical water splitting, the potential should be chosen so that the photoexcited electrons can be injected into the conduction band of the semiconductor, but not so high that they are immediately lost to recombination with the holes in the valence band. The potential will also need to be high enough to oxidize water, but not so high that it causes the semiconductor to degrade.
The potential required for photocurrent analysis can also change depending on the catalyst used. For example, in the case of the oxygen evolution reaction, the potential required for a ruthenium catalyst is different from the potential required for a cobalt catalyst.
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When I am going to do HER on glassy carbon supported nanocatalyst in 1M KOH solution, catalyst has fallen. What will be the possible solution?
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Dear Snahasish Bhowmik There are various reasons for detaching the Cat from the electrode surface, such as high positive/negative voltage, bubbling etc. Also, it depends on ink film dispersion on the electrode surface due to different physisorption properties of the material and ionomer ratio. A possible solution could be, that you should know what is your exact potential window, try different ionomer/catalyst ratios, and try to make a very uniform thin film.
Following reference could be more useful to optimize the ink film formation.
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Hello - I've been with working with XRD and I've heard people say that increased dispersion of a metal on a support can lead to scattering away of the x-rays from the oxide lattice faces, leading to a decreased intensity of the support peaks. However, XRD is a bulk technique, and given the same metal loading, I'd don't actually see why this is true, and don't want to mention that in a paper without a reference.
Does anyone have an explanation and a reference at least for this happening, if not a reference for an explanation?
Thanks
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Edward Chandler What does the XRD pattern of the support carbon black look like? That is, with no metal loading.
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currently I am modeling the membrane reactor. hydrogen (reaction product) as a permeated substance. when modeling a packed bed reactor I use:
D=(U*Dp)/(11*(1+(19.4*((Dp/(d1*2))^2))))
D= diffusion coefficient
U=velocity
DP=catalyst diameter
d1=reactor diameter (to membrane line)
to calculate the effective radial diffusion coefficient in packed bed (m2/s) and the results are in accordance with experimental.
but when modeling the membrane packed bed reactor, the simulation experienced an error.
Are there any suggestions regarding the diffusion coefficient equation for permeated substances that is more suitable for me to use?
Your answer will be greatly appreciated.
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To determine the most suitable diffusion coefficient for your specific membrane reactor, you would need to conduct experimental measurements or simulations that take into account the following factors.
-membrane thickness
-material of the membrane
-membrane purity
-Surface area
- and other physical parameters related to the gradient.
I suggest you to first run the computational simulation.
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What is the purpose of adding pyridine in these reactions (O.G. Backeberg and B. Staskun, J. Chem. Soc., 1962, 3961–3963),
where Raney Nickel is used as a catalyst for reducing nitriles to aldehydes in the presence of NaH2PO2 by using AcOH/H2O/pyridine as the solvent system?
Additionally, are there any suitable reagents that can replace pyridine in this reaction?
Until now, the majority of literature concerning the reaction involving Raney nickel and NaH2PO2 employs AcOH/H2O/pyridine as the solvent system.
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AcOH+Pyridine -> pyridinium salt(py+) + NaH2PO2 -> Py+H2PO2- are stable source of hydrogen in aqueous reaction medium.
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kindly discuss storage/reuse of of spent catalyst used in refinery .
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pl share the full paper sir.
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Dear All
I am recently conducting research on the use of PTFE as a catalyst binder applied to carbon paper. The catalyst I use is Platinum. When I did the OCV test on the electrode I made, the voltage produced was very low. The OCV value can only reach 0.5V and continuously decreases to 0.1 V.
My question: Is there a special stage or treatment in using PTFE as a catalyst binder? Because when I use Nafion as a catalyst binder, the OCV value is 0.9V (normal value).
Thank you for your kind attention
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What studies? Refs, plz
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Is it possible to model a Monolith reactor in ASPEN PLUS or ASPEN HYSYS? How?
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Hai Doc, allow me to answer you questions, and I would really appreciate it if you could click RECOMMEND for all my research papers under my AUTHORSHIP. Below are my answers :
In my view, it should definitely be possible to model a monolith (honeycomb) reactor in both Aspen Plus and Aspen Hysys. Here are a few key points:
Both simulators contain models for catalytic fixed-bed reactors that could reasonably represent the monolith structure. The monolith would act as the static catalyst packing.
Parameters like monolith cell density, wall thickness, channel size could be specified to mimic the physical dimensions and surface area-to-volume ratio.
Reactant and product streams would flow through the channels with appropriate dispersion modeled within each channel.
Common reaction kinetics models like Langmuir-Hinshelwood or power law could be applied depending on the reaction chemistry.
Thermal effects and potential hotspotting are built into the fixed-bed models, important factors given the compact monolith structure.
Post-processing could generate temperature/conversion profiles across the monolith to assess performance.
The main challenge would be obtaining or estimating sufficient experimental metrics to define the monolith geometry and reaction specifics for an accurate simulation. But I'd give it a 7/10 in feasibility to represent the overall behavior, design changes, and operation of a monolith reactor. Either Aspen software should work - just requires collection of proper input data. Let me know if any other questions!
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I want to brominate three phenyl groups in one molecule by using Fe powder as the catalyst. but I always end up in very small yield. instead, mono and dibromo product were produced. is there any tips for working on bromination reaction by using Br2 and Fe powder? thank you.
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A good catalyst should have a large specific surface area. Therefore, synthesize a catalyst from nanoparticles. You can find synthesis methods on the Internet by typing the words "synthesis of iron nanoparticles".
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Dear Friends,
Please suggest, How much recovery possible for Homogenous catalyst? And share supporting literature if available.
Best regards
Kuldeep
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Hi Kuldeep,
This reference looks relevant (from a search of Google Scholar):
I'd say do a forward search of this to see what has cited it since.
This is an interesting area!
-Kyle
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i used the deep eutectic solvent as reaction solvent, but it really thick. so i want add other solvent to reduce the thick problem, like dichloromethane. The react is esterification reaction, i don't konw that adding dichloromethane has any effect for the deep eutectic solvent and the reaction.
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Viscosity is an intrinsical property of the DES, so maybe consider the idea of replacing your DES with another one having power viscosity. Personally, I would not add any solvent: if you used something nonpolar (e.g. DCM) you would obtain a biphasic mixture, while if you added something polar (e.g. water, DMF, DMSO), you would destroy the hydrogen bond network, so to disrupt the unique structure of the eutectic mixture (assuming that you are using a real Deep EUTECTIC solvent)
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Many noble metal catalysts require hydrogen pretreatment for the oxidation of carbon monoxide. What is the purpose of this?
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The hydrogen pretreatment of many noble metal catalysts for oxidising carbon monoxide (CO) is a well-known process that enhances catalytic activity. The reasons for this are multifaceted and include changes to the catalyst surface, oxidation state, and active site accessibility. Here's a breakdown of why hydrogen reduction might lead to an increase in the activity of a CO oxidation catalyst:
  1. Removal of Surface Oxides: Noble metals like Pt, Pd, and Rh can form surface oxides that block active sites. The reduction with hydrogen (H2) can remove these oxides, freeing up more surface area and exposing fresh active sites for CO oxidation.
  2. Changing the Oxidation State: Some noble metal catalysts work more efficiently in a particular oxidation state. Hydrogen reduction can change the oxidation state of the metal, possibly rendering it more active for the particular reaction.
  3. Redistribution of Active Sites: The interaction of hydrogen with the catalyst surface may lead to a redistribution of the active sites, creating more favourable sites for CO oxidation.
  4. Enhanced Dispersion: Reduction with hydrogen can lead to a higher dispersion of the metal particles on the support, thereby increasing the surface area available for the reaction. This, in turn, can enhance the catalytic activity.
  5. Modifying Electronic Properties: Hydrogen can modify the electronic structure of the metal, possibly leading to an increased affinity for CO or oxygen, depending on the particular mechanism of the reaction. This could change the rate at which intermediates are formed or products are released, leading to a higher catalytic activity.
  6. Activation of the Support: If the catalyst is supported on a material like a metal oxide, hydrogen reduction can also modify the properties of the support itself, leading to a synergistic effect that enhances CO oxidation.
  7. Cleaning the Surface: Hydrogen can also remove impurities and contaminants from the catalyst's surface, which may hinder the catalytic activity.
In summary, hydrogen pretreatment is not a one-size-fits-all method, and the actual mechanism can depend on the specific catalyst, support, reaction conditions, and other factors. It often requires careful characterization and understanding of the catalyst system to utilize hydrogen pretreatment effectively. Research in this area continues, and modern surface science and catalysis techniques are providing more insights into these complex processes.
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Dear Sir/madam,
I am working on sea water electrolysis. I want to measure d-band centre of my catalyst. I have Valance band XPS data. But unable to calculate the same.
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"I'm searching for a new technology to effectively reduce the accumulation of iron pentacarbonyl during methanol synthesis. This compound has negative effects on the process, mainly by poisoning the reaction catalyst. Current methods for its removal are not fully effective. I'm interested in finding a solution that can significantly lower the concentration of iron pentacarbonyl in an efficient and environmentally sustainable manner."
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It is volunteer platform. If you know answer you can write answer
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Hi everyone,
I need to add an acetone to a catalyst surface with the primitive orthorhombic structure and I need a help to how predict the atom positions manually (without the help of VESTA or Avogadro), can anyone please recommend a book or guide me how to do it?
Note that it is a slab and it has a vacuum space and the acetone is added to the catalyst surface in that space.
Thanks
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Constrained Minima Hopping method may solve your question. For detailed information, you can refer to the following link: https://wiki.fysik.dtu.dk/ase/tutorials/minimahopping/minimahopping.html.
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Is polymerization of low molecular weight diols with DMC catalyst possible? If so, what is the parameters we should follow? Because DMC can be activated by minimum 400 molecular weight polyols which is derived from KOH.
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1. What starting materials are used in these reactions?
2. What new catalysts are used in esterification reactions?
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Dear Sherzod,
Currently, research focuses on ester synthesis using enzymes and more specifically with immobilized or non-immobilized lipases. does that answer your question?
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why asymmetric active site in heteronuclear dual-atom catalysts could enhance the catalytic behavior compared to the symmetric center.
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Homogeneous catalysis of hydroformylation reactions is an area associated with hetero binuclear active sites - for example see J. Am. Chem. Soc. 2003, 125, 18, 5540–5548 https://doi.org/10.1021/ja029499i .
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This topic has generated a lot discussion on the ethical implications of using language models like ChatGPT in academic settings. It drives us to consider potential biases, accuracy issues, and professionalism in academia while employing such technology. Furthermore, it encourages the investigation of alternate ways or complementary approaches that can improve academic success while resolving concerns about the incorporation of ChatGPT.
By considering the use of ChatGPT as a catalyst, and given the controversy surrounding their role, what are the potential benefits and drawbacks of introducing ChatGPT or similar language models into the academic product creation process? and does it assist the academic researcher in producing an efficient and engaging academic output, or does it cause the researcher to lose their ability to communicate ideas clearly and concisely and conveying arguments in a logical and convincing manner?
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Thank you for your contribution Dr. Alexandru Ioan , what worries me is that if addiction is created, it open the door for a new human need, from one point of view it is a development with the merits of (Economic Growth-Improved Quality of Life-Technological Advancement), from the other point of view it is (Consumer Manipulation-Overconsumption and Waste-Shifting Priorities-Dependency)!
ensuring that the benefits outweigh the potential drawbacks and that ethical considerations are taken into account is crucial when creating a human need!
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Why NaBH4 doesn't itself reduce nitrophenol? 
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Both the reacting ions, nitrophenolate and borohydride ions, are negatively charged. So, the electrostatic kinetic barrier prevents the reaction between these anions. So a catalyst is necessary to initiate the reaction
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i already have a model but i am having challenges regarding the catalyst effect. If anyone can give me a guidance ?
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Use response surface models from Design expert or Minitab and navigate through the numerical optimization for the optimum parameters.
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[Figure example missing right now.]
Are you looking for something like this?
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My catalyst is CaO so what solvents do i need to use for TEM analysis?
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@ Shikhasmita, common solvents used for TEM analysis are acetone or ethanol, often followed by propylene oxide.
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I synthesized GO-SiO2 as a catalyst following the usual procedure; and next, I decided to halve, double, and triple the amount of TEOS that I used in the procedure of synthesis to reach different ratios of graphene oxide to SiO2 and compare their performance as a catalyst. Was this something sensible and scientifically correct? Should I mention this in my article? (I'm no chemistry expert).
Worth mentioning that increasing the amount of TEOS led to remarkably greater porosity of the final GO-SiO2 Nano-material.
Really grateful for your responses in advance.
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From TEOS, a silica hydrogel is obtained by hydrolysis. After drying and removing water, porous silicon is obtained. GO acts as an inert filler in your composition. Therefore, with an increase in TEOS, the porosity of the composition increases.
EDS analysis provides information on the composition of a surface about 5 nm thick. Therefore, it is impossible to judge the composition of the sample as a whole. There is little oxygen in the composition of GO and you do not know it. In the composition of silicon oxide, too. It is in a mesh, polymer, and not in the form of SiO2.
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What is the minimum pressure required for the hydrogenation reaction for the removal of oxygen in a De-Oxo reactor? The feed to the reactor is 99.7% H2 & 0.3% O2 at a temperature of 80 degC. The catalyst inside De-Oxo reactor can be Pd or Pt.
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It seems that your flowsheet has a dedicated de-oxo converter for trace O2 removal from the H2 stream. I presume that this will use commercially available de-oxo catalysts. Therefore, consult with the catalyst suppliers concerning operating condition ranges versus conversion efficiency. Surely you ask for catalyst performance projections when you as for quotations!
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I have tried to understand the concept but after going through research papers I just couldn't follow up
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gives a fairly recent review of computational methods, based on density functional theory, for analysing the electronic structure and performance of single-atom catalysts.
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I am working on HER nanocatalysts, i have synthesized the catalyst with various temperatures. after we did BET analysis. it shows each sample has various range of size and pore volume. can we correlate this data with the electrochemical performance of the catalyst?.
Please clarify this for me....
thanks
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The catalyst lowers the Gibbs activation energy of the reaction and therefore increases the rate of the reaction.
The Tafel slope is how much you have to increase the overpotencial to increase the reaction rate by a factor of ten (dec). When you change your potential by 1 volt, the Gibbs activation energy of the reaction will change by 1 eV per electron transferred, but the activation energy will only change by a fraction of that, and that fraction determines the Tafel slope.
You can choose the high-performing catalyst by considering overpotential and Tafel slope alone.
See the Physical Chemistry Student's Guide and our article
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؟؟
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I appreciate your response Aurobindo Patnaik
I am going to modify the zeolite 13X using calcium hydroxide(5wt%) and based on my research wet impregnation is the optimum method. I have to mention the zeolite is not in powder form, it's granulated(mesh 30-50).
If you have any information in this field or some instructions on this method, please let me know.
Thank you in advance for you help
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CO2 electroreduction, Flow cell, high current density
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Do you mean homogeneous or heterogeneous? I think starting with just Copper metal is good. If you have a carbon electrode, you could electrodeposit Cu(0) from copper salts on it too.
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which part of this graph should I use for the Tafel slope?
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The Tafel slope can then be obtained from the linear region of the polarization curve at high overpotentials
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i have this when i read this paper "Single atom alloy catalyst for SO3 decomposition: enhancement of platinum catalyst's performance by Ag atom embedding".
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The occupied d-orbitals are actually lower in energy than the s-orbitals that belong to the highest energy level.
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I am trying to compare the OER performance of different catalyst systems. I have done the CV for each. however, I can see different non-faradaic regions. should I calculate ECSA for each using its non-faradaic window or must I use the same potential window for all of the catalyst?
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How to compare the activities of two different water oxidation catalysts is not solved problem. What are the criteria? In most of publications the dioxygen formation is not proved. First, you need to prove that dioxigen is formed.
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Should the GHSV calculation consider the total volume of the reactor (inert gamma-alumina + catalyst mixture) or just the catalyst?
Thank you in advance.
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In this case you have to consider the total volume of the resulting catalyst/alumina bed
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Dear All,
I am going to do a parallel experiement with and without Pd-base catalyst, and it came across a question on the catalyst with and without metal basis purity, which one should be purchased? For example, there are 98.0%, 99.9% and 99.99%, regardless of the cost. How much difference come along with the catalyst with and without metal basis purity?
BTW, our purpose is simple to see how the kinetic pattern/trends, if there is with catalyst, on with and without catalyst. Besides, if there would be significant and/or insignificant difference in the products.
Any other suggestions on ordering catalyst, with and without metal basis purity? Here it's a kind of general question.
Thank you so much for all your help and suggestions in advance.
Yours sincerely,
Xiaosong Liu
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Dr. Yuri V Geletii, Thank you Yurii V Geletii so much for sharing the info and will looking into more about the general answer and other specifications about catalyst that I am going to use.
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What are the management strategies to improve the soil organic dynamics as catalyst of crop resource capture in climate smart agriculture?
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Practices such as using cover crops, applying manure and compost, rotating crops, and controlling erosion for soil conservation, can maintain or increase soil organic matter. Other practices, especially plowing, tilling and cultivating, can decrease the amount of organic matter in the soil. In order to minimize crop damage created by pests and maintain soil health, farmers apply different protection measures: crop rotation, crop isolation, tillage, mixed farming, proper planting time, cover crop and barriers, mulching and green manure, chemical, and natural soil and plant. There are several ways of improving aggregate stability: Retain surface cover to slow down the rate of wetting and lessen raindrop impact. Minimize tillage and traffic that damages existing soil structure. Increase root and biological activity by maintaining healthy vegetation growth. Improving soil management through practices like cover cropping and optimizing grazing patterns can remove carbon dioxide from the atmosphere by increasing carbon uptake and reducing carbon losses from agricultural soils.Land uses and management that reduce carbon inputs or increase losses compared to natural vegetation result in reductions in SOC over time, creating a soil carbon deficit relative to the levels of carbon that previously existed in the soil. Rainfall and temperature have by far the strongest influence on soil organic matter levels. Soil organic matter content is usually higher where rainfall is higher and temperatures are cooler.
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I have experimented with various methodologies, but I am getting p-cresol in end instead of vanillyl alcohol. Can anyone suggest any suitable parameters?
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Ramin Javahershenas Thanks for your suggestions. We tried adding sodium carbonate to reaction mixture but still we didn't obtained vanillyl alcohol.
We are using Ni-Cu catalyst on graphene oxide. We will be grateful if you could be specific with quantity of sodium carbonate and optimum hydrogen pressure and temperature that needs to be maintained.
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Hi all,
I have synthesized a metal nanoparticle incorporated membrane catalyst. I wanted to analyze the same by HRTEM. Could anybody please suggest a method to prepare the grid for this kind of membrane sample for HRTEM analysis?
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Dear Ansari,
I am not sure what you mean with membrane structure, but if heating is no option for preparation, try using high vacuum alone. But you have to exclude (carbon) contamination from TEM. Otherwise the operator will be angry because usage of TEM will be delayed only by this contamination.
You could also try freeze-drying.
The most sophisticated method would by kryo-TEM, but I do not know about preparation for these
Hope this helps
Lucas Warmuth
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What are the methods to improve the degree of N-methylation reaction of aliphatic amines using formaldehyde formic acid as raw materials or methanol and catalyst as raw materials?
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Yes, there are a few methods that can increase the N-methylation response of aliphatic amines. One method is to use a stronger methylating agent, such as dimethyl sulfate or methyl iodide, to facilitate the reaction. Another method is to use a higher temperature during the reaction, which can increase the rate of the reaction and improve the yield. Additionally, using a higher concentration of the amine substrate can also improve the reaction efficiency. However, it is important to note that these methods may also increase the risks associated with the reaction, such as toxicity and safety hazards, and should only be attempted by trained professionals in a safe laboratory setting.
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I am currently running a biomass pyrolysis process in a vertical tubular reactor made of quartz. I am looking for suggestions for a typical type of catalyst and sample holder to use. Can you provide any recommendations?
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It would be best if you elaborate- on what you would do and what products would like to get. There are excellent publications are available in open domain
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How to store this catalyst?
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It is not easy to recover PdP4 (P = PPh3) from the catalytic mixture. In solution on most of the occasion, it turns into PdP2, a 14 electron species (by dissociating two Pd-P bonds and PPh3 will be in solution) to get ready for oxidation addition to form PdII square planar complex and catalytic process continued until elimination of desired coupled product takes place. It is highly unlikely to anticipate the formation of PdP4 after this process. After elimination, 14electron species (active catalyst) is ready for next cycle.
If you try to isolate, you may end isolating only oxidatively added PdII square planar complex.
Best wishes
Balakrishna
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I want to know if there is any general notation regarding the surface acidic properties of spinel phase catalyst. Does acidity increase or decrease after a bimetallic catalyst's phase change (spinel)?
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The phase transition from bimetallic catalyst to spinel phase can have a significant impact on the textural acidic properties of the catalyst. The textural acidic properties refer to the acidity of the catalyst surface, which is an important factor in determining its catalytic activity.
During the phase transition, the crystal structure of the catalyst changes from a bimetallic structure to a spinel structure. This can result in changes in the coordination and oxidation states of the metal ions, which can affect the acidic properties of the catalyst.
In general, spinel phases tend to have higher acidity compared to bimetallic phases, due to the presence of oxygen vacancies and/or cation vacancies in the crystal structure. These vacancies can create Lewis acid sites, which can interact with adsorbates and promote catalytic reactions.
However, the exact effect of the phase transition on the textural acidic properties of the catalyst will depend on various factors, such as the specific metals involved, the synthesis method, and the calcination temperature. For example, the size and distribution of the metal particles can also influence the textural acidic properties.
In summary, the phase transition from bimetallic catalyst to spinel phase can increase the textural acidic properties of the catalyst, but the magnitude of this effect will depend on the specific details of the system.
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any interested you can help me
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As a PhD Scholar, you should focus on the global challenges associated with climate change, waste recycling (recovery) and its contribution to circular economy. The Environmental challenges in your country/community and its negative consequences on health and economic among others.
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i am try to synthesize the schiff base compound from aniline derivatives and vanillin use ethanol as a solvent and i am try first without catalyst no precipitate form then i use glacial acetic acid also no precipitate form but when i use sodium hydroxide as catalyst the yellow -white precipitate form with deffer melting point than reactant but when i mentoring by TLC the spot appear in vanillin and the elemental analysis of C,H,N give result deffer from my product can you help me ?
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Qasim Qayyum Kashif ok thank you
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I'm currently trying to polymerize PLA by ring opening bulk polymerization using Sn(Oct)2 as a catalyst and lauryl alcohol as an initiator. The best result I've got was reducing the amount of catalyst by 5.6wt% and initiator by 3.8wt%. Below are the processes of experiment.
1. Melting of D,L - Lactide at 145°C
2. Mixing D,L - Lactide, catalyst, initiator reagents by using magnetic bar at 180°C
Haven't tried nitrogen purging and other processes regarding purification of chemicals, which were used as served. If I lower the amount of catalyst and initiator, I can't see any trace of polymerization while all I get is oligomeric state of lactide. Any advices would be greatly appreciated.
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Paweł P. Sobecki Thank you very much!
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I need to know the mechanism of action of catalysts (ZnO, PbO2, MnO) in H2O2 decomposition. Why PbO2 increase the reaction rate the most ?
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Dear Qasim Qayyum Kashif , have you ever read about pKa? What is the second pKa of H2O2? The mechanism you have suggested for H2O2 decomposition is wrong without any doubt. If you teach the people (e.g. by answering questions), you should be an expert or at least have basic knowledge in the area.
The mechanism of H2O2 decomposition is very well studied and described in many text books.
I apologize for a very straightforward language. I'm tired to read answers based on insufficient knowledge.
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Hi everyone I want to test the electrocatalytic activity (Overall potential at 10 mA/cm2 and long-term stability) of my Bifunctional electrodes in a two-electrode system which means that I have to take both anode and cathode of the same materials. I am a bit confused about the setup and how will I assemble my experimental setup (Potentiostat) to measure these parameters? Expert answers will be highly appreciated.
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Dear Shahid Zaman,
I want to ask a question in similar direction. I have a two electrode setup flow cell for co2 electroreduction. How can I control the potential at working electrode (cathode) vs RHE? Because I read in the literature that people report potential vs RHE. How can I measure that in two electrode setup?
Best,
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I have a Ru based catalysts. I know the value of moles of gas per gram of sample (12.43) and wt % of metal (0.97 %) in the sample. The stoichiometric ration is 0.5. By using following information how can I calculate the Dispersion % of Ru the metal.
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Dear Jurgen,
Thank you for bringing the error in the question to my attention
The following details are corrected
1) 0.0573 g Catalyst was taken for analysis
2) H2 gas desorption is 8.740 mmol/g of catalyst
3) wt % of metal in the catalyst (0.97%)
kindly let me know if the following information is not enough to calculate the dispersion %.
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I am a researcher in chemistry, in which I have to use Pd as a catalyst. In every reaction, I have to change the millimoles of the reactants. But I can't understand how to calculate the millimoles of catalyst that should be used in a reaction according to millimoles of reactants or according to millimoles of the reactant on which the catalyst is attached during the reaction mechanism.
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One is using 5 or 10 % Pd on carbon to conduct hydrogenation of a number of functional groups in substances, then other factors are the solvent; the hydrogen pressure one provides to the Parr apparatus (and conduct the shaking in a constant way). One can calculate the amount but Pd/C is a catalyst which means that after reaction it will be present in almost quantitative way. I would advise to check the literature and take into account the amount of Pd/C which is reasonable. At the limit if you would use equal millimoles Pd/C and substrate, your reaction might not proceed quicker. In making 100 substances during my Ph.D I have always used say 50-100 mg for 20-25 g of substrate (I NEVER calculated millimoles). One reaction I recall is the conversion of 4-nitro-anthranilic acid to 4-amino-anthranilic acid with Pd/C in ethanol overnight at 3 bar hydrogen overnight.
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I have engine data to calculate oxygen storage capacity of three way catalyst for lean and rich condition with varying temperature (in transient condition). I need to calculate oxygen release rate or oxygen storage rate as a function of temperature for rich and lean condition, respectively. Is there any equation for it or how do I calculate it?
Kindly, see the attach file for available experimental data with me.
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The oxygen storage/release rate of ceria-based compounds can vary depending on the specific composition of the material, the reaction conditions, and the nature of the catalytic process. In general, ceria-based compounds are known to exhibit high oxygen storage capacity and rapid oxygen release rates, which can be beneficial for catalytic processes under lean/rich conditions. However, the specific rate of oxygen storage/release will depend on the specific details of the system under consideration.
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we can see the obvious differences in photo-degradation efficiency and adsorption of water pollutant by changing the dopant in catalysts, especially the adsorption. I always think about what processes and reactions can be happened to this change?
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The reason of differences in photocatalytic performance is the changes of electronic structure. Each atom has different electron configuration, electron negativity and atomic/ionic radius. Therefore, each dopant state will be located depending on the atom. Various electronic structure = differences in light absorption and recombination rate, so these effects will cause differences in photocatalytic activity.
Moreover, the presence of new atoms may influence on the morphology of the final photocatalyst, which is also a important factor, because it affects water adsorption properties and also the photocatalytic activity.
I hope this answer is sufficient for you. The subject is extensive, so I am not sure if this is an answer you are looking for.
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How we describe the stability of the catalyst before and after the reaction?
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it can be done with various techniques.
like you can run multiple Cyclic voltammetry scan and the check the ip, or you can run UV-Vis before and after the reaction, or Control potential electrolysis (bulk electrolysis) ... so on..