Javier Ruiz-Martínez

Javier Ruiz-Martínez
King Abdullah University of Science and Technology | KAUST · KAUST Catalysis Center (KCC)

PhD

About

119
Publications
19,762
Reads
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5,169
Citations
Additional affiliations
October 2009 - present
Utrecht University
Position
  • Researcher
December 2003 - September 2009
University of Alicante
Position
  • PhD

Publications

Publications (119)
Article
Full-text available
Photo‐thermal catalysis, leveraging both thermal and non‐thermal solar contributions, emerges as a sustainable approach for fuel and chemical synthesis. In this study, an Fe‐based catalyst derived from a metal–organic framework is presented for efficient photo‐thermal ammonia (NH3) decomposition. Optimal conditions, under light irradiation without...
Article
Full-text available
Operando UV-vis spectroscopy reveals that highly alkylated benzenes and long-chain oligomers are major deactivating species in zeolite-catalyzed propene oligomerization.
Article
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As a half‐reaction in anion exchange membrane water electrolysis (AEMWE) technology, the hydrogen evolution reaction (HER) at the cathode is severely hindered by the sluggish reaction kinetics involved in additional water dissociation step, which results in large overpotentials and low energy conversion efficiency. Here, we develop a nano‐heterostr...
Article
Here, we develop a nano‐heterostructure composed of ultra‐thin W5N4 shells over Ni3N nanoparticles (Ni3N@W5N4) as efficient catalysts, in which built‐in interfacial electric field (BIEF) is created owing to the distinct lattice arrangements and work functions of biphasic metal nitrides. The BIEF facilitates the electron localization around the inte...
Article
Full-text available
Given that ethanol can be obtained from abundant biomass resources (e.g., crops, sugarcane, cellulose, and algae), waste, and CO2, its conversion into value‐added chemicals holds promise for the sustainable production of high‐demand chemical commodities. Nonoxygenated chemicals, including light olefins, 1,3‐butadiene, aromatics, and gasoline, are s...
Article
The efficacy of the methanol-to-aromatics process over ZSM-5 was evaluated considering factors such as hierarchy, particle size, and bifunctionality.
Article
The tandem CO2 hydrogenation to hydrocarbons over mixed metal oxide/zeolite catalysts (OXZEO) is an efficient way of producing value-added hydrocarbons (platform chemicals and fuels) directly from CO2via methanol intermediate in a single reactor. In this contribution, two MAPO-18 zeotypes (M = Mg, Si) were tested and their performance was compared...
Article
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The artificial photosynthesis of hydrogen peroxide (H2O2) is of great interest, yet it poses a significant challenge in simultaneously boosting the oxygen reduction reaction (ORR) while maintaining an efficient water...
Article
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Controlling selectivity in the hydrogenation of compounds with several functional groups remains a challenging task in heterogeneous catalysis. We report herein the design and use of simple catalysts composed of...
Article
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Metal encapsulation in zeolitic materials through one‐pot hydrothermal synthesis (HTS) is an attractive technique to prepare zeolites with a high metal dispersion. Due to its simplicity and the excellent catalytic performance observed for several catalytic systems, this method has gained a great deal of attention over the last few years. While most...
Preprint
Full-text available
Zeolites have been successfully applied on a wide range of reaction processes (Methanol to Hydrocarbons, Fluid Catalytic Cracking, etc) and continue to attract academic and industrial investigations. Understanding of the reaction mechanisms involved in zeolite catalysis has been a long standing issue due to the wide range of intermediates and produ...
Article
Full-text available
Metal encapsulation in zeolitic materials through one‐pot hydrothermal synthesis (HTS) is an attractive technique to prepare zeolites with a high metal dispersion. Due to its simplicity and the excellent catalytic performance observed for several catalytic systems, this method has gained a great deal of attention over the last few years. While most...
Preprint
Full-text available
Providing a complete scheme to describe the methanol-to-hydrocarbons (MTH) reaction network is impeded by insufficient understanding of the chemistry occurring incipiently. Using a temperature-dependent reaction strategy, combined with operando photoelectron photoion coincidence (PEPICO) spectroscopic diagnosis of intermediate species and theory, w...
Article
Full-text available
Wet-kneaded silica–magnesia is a benchmark catalyst for the one-step ethanol-to-butadiene Lebedev process. Magnesium silicates, formed during wet kneading, have been proposed as the active sites for butadiene formation, and their properties are mainly explained in terms of the ratio of acid and base sites. However, their mechanism of formation and...
Preprint
Full-text available
The reliance on methanol as an alternative and sustainable source to produce monoaromatics is challenged by many side reactions. Although the strategy of intentionally incorporating a number of active functionalities (metals and acid sites) in individual catalyst particles can enhance product selectivity, it promotes undesired hydrogen-transfer rea...
Article
Full-text available
The selective oxidation of CH4 in the aqueous phase to produce valuable chemicals has attracted considerable attention due to its mild reaction conditions and simple process. As the most widely studied catalyst for this reaction, Fe-ZSM-5 demonstrates high intrinsic activity and selectivity; however, Fe-ZSM-5 prepared using conventional methods has...
Article
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Tungsten is the most interesting and promising metal to replace molybdenum in methane dehydroaromatization (MDA) catalysis. Located in the same column of the periodic table, tungsten displays similar chemical features...
Article
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The increasing demand for base chemicals i.e., ethylene and propylene, along with the expected peak in gasoline and fuels demand, are stirring intense research into refineries to be built around...
Preprint
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The selective oxidation of CH 4 in the aqueous phase to produce valuable chemicals has attracted considerable research attention due to its mild reaction conditions and simple process. As the most widely studied catalyst for this reaction, Fe-containing ZSM-5 zeolite (Fe-ZSM-5) demonstrates high intrinsic activity and selectivity; however, Fe-ZSM-5...
Article
The stability of anatase titania nanoparticles was investigated under exposure to repeated loading of shockwaves produced in a diaphragm-driven high-pressure shock tube. The titania samples were exposed to 20 shocks with pressure, temperature, and steady exposure time in the range of 20.5 – 26 bar, 1399 – 2101 K, and 1.74 – 1.83 milliseconds, respe...
Article
Full-text available
Mn-based oxides are promising for the selective catalytic reduction (SCR) of NOx with NH3 at temperatures below 200 °C. There is a general agreement that combining Mn with another metal oxide, such as CeOx improves catalytic activity. However, to date, there is an unsettling debate on the effect of Ce. To solve this, here we have systematically inv...
Article
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Photo-thermal catalysis has recently emerged as a viable strategy to produce solar fuels or chemicals using sunlight. In particular, nanostructures featuring localized surface plasmon resonance (LSPR) hold great promise as photo-thermal catalysts given their ability to convert light into heat. In this regard, traditional plasmonic materials include...
Preprint
Full-text available
Wet-kneaded silica–magnesia is a benchmark catalyst for the one–step ethanol-to-butadiene Lebedev process. Magnesium silicates, formed during wet-kneading, have been proposed as active sites responsible for butadiene formation, and their catalytic performance has been mainly explained by the variations in the ratio of acid and base sites. While the...
Article
Full-text available
In this work, the poisoning effect of SO 2 was investigated in binary MnTi and ternary MnCeTi mixed oxides for the NH 3 -SCR reaction under conditions relevant for mobile applications. For the...
Preprint
Full-text available
Mn-based oxides are promising catalysts for the selective catalytic reduction (SCR) of NOx with NH3 at temperatures below 200 °C. There is a general agreement that combining Mn with another metal oxide, such as CeOx improves catalytic activity. However, to date, there is an unsettling debate on the role of Ce as Mn promoter on the SCR reaction. To...
Article
The effect of copper on various acid saponite supported Ni-Cu bimetallic catalysts, prepared with different Ni : Cu ratios, was studied for the liquid phase hydrogenolysis of glycidol on a batch reactor at 393 and 453 K. Characterization of the catalysts showed that Ni and Cu are in close contact as the XRD measurements evidenced the formation of a...
Article
Full-text available
The methanol-to-aromatics (MTA) process is regarded as a promising route to produce aromatic commodities through non-petroleum carbon resources, such as biomass, waste, coal, natural gas, and CO2. In contrast with the industrially implemented methanol-to-olefin (MTO) process, most MTA studies are still in the laboratory-scale stage. Recently, a few...
Article
In the current petrochemical market, the global demand for aromatics, especially benzene, toluene, and xylenes (BTXs), has increased sharply. The methanol-to-aromatic conversion (MTA) over ZSM-5 is among the most promising routes to satisfy this ever-growing demand. In this work, we show that high-pressure operation during MTA leads to a large incr...
Article
Full-text available
The Lebedev process, in which ethanol is catalytically converted into 1,3-butadiene, is an alternative process for the production of this commodity chemical. Silica–magnesia (SiO2–MgO) is a benchmark catalyst for the Lebedev process. Among the different preparation methods, the SiO2–MgO catalysts prepared by wet-kneading typically perform best owin...
Article
Containers of chemical species: The painting illustrates a bottle and a vase containing chemical species. In a bottle, like in the case of SAPO‐18 and similar structures, the species that are larger than the bottleneck cannot exit and remain trapped inside (ship in a bottle). Contrariwise, in a vase with no bottleneck, like in the case of ZSM‐5 and...
Article
Full-text available
The dynamics of the retained species on ZSM‐5 and SAPO‐18 catalysts are studied by using a combination of temperature‐programmed desorption/oxidation, ex situ analysis, and in situ FTIR spectroscopic measurements over the entire conversion range, using fixed‐bed and spectroscopic cell reactors, in continuous and discontinuous mode. The results poin...
Article
Confining metal active species in the voids of porous solid matrices such as zeolites, metal–organic frameworks (MOFs), and carbon nanotubes (CNTs) can bring fascinating key advantages in the field of selective hydrogenation reactions. Confined metal species act as intermolecular selective catalysts capable of discriminating reagents based on their...
Article
Full-text available
The deactivation of Sn-Beta zeolite catalyst during retro-aldolization and isomerization of glucose is investigated. Confocal fluorescence microscopy reveals that retro-aldolization of glucose in CH3OH at 160 °C is accompanied with the build-up of insoluble oligomeric deposits in the micropores, resulting in a rapid catalyst deactivation. These dep...
Conference Paper
The presentation related to an explanation about an unfamiliar and interesting material called partially crystalline H-ZSM-5 that possess unique properties to enhance the propylene selectivity in methanol-to-olefin reaction
Article
Full-text available
The gas-phase aldol condensation of propanal, taken as model for the aldehyde components in bio-oils, has been studied with a combined operando set-up allowing to perform FT-IR & UV–Vis diffuse reflectance spectroscopy (DRS) with on-line mass spectrometry (MS). The selected solid base catalysts, a cesium-exchanged X zeolite (Cs-X), a calcium hydrox...
Article
Full-text available
The selectivity toward lower olefins during the methanol-to-olefins conversion over H-SAPO-34 at reaction temperatures between 573 and 773 K has been studied with a combination of operando UV–vis diffuse reflectance spectroscopy and online gas chromatography. It was found that the selectivity toward propylene increases in the temperature range of 5...
Article
Full-text available
The nature and evolution of the hydrocarbon pool (HP) species during the Methanol-to-Olefins (MTO) process for three small-pore zeolite catalysts, with a different framework consisting of large cages interconnected by small eight-ring windows (CHA, DDR, and LEV) was studied at reaction temperatures between 350 and 450 °C using a combination of oper...
Article
This study explores the use of glycidol, as alternative to glycerol, to improve the selectively to 1,3-propanediol (PrD) by hydrogenolysis. The reaction was performed using Ni (with different Ni wt %) supported on an acid delaminated saponite catalysts which are cheaper compared to the expensive catalysts needed to favor the 1,3-PrD formation by gl...
Article
The Front Cover shows Ca-ZSM-5 as a “super-catalyst” fighting coke – the evil of MTO world.In their Full Paper, I. Yarulina et al. investigated the mechanism of methanol to olefins (MTO) reaction, which is characterized by the presence of two competing cycles – olefinic and aromatic. The latter is responsible for catalyst deactivation since aromati...
Article
The front cover artwork for Issue 19/2016 is provided by researchers from the Catalysis Engineering group at TU Delft (The Netherlands). The image shows that after impregnation with Ca, ZSM-5 becomes a “super-catalyst”, which is able to suppress formation of aromatics thus increasing selectivity to the desired propylene in MTO reaction. See the Ful...
Article
Full-text available
Operando UV-Vis spectroscopy with on-line mass spectrometry was used to study the effect of different types of impurities on the hydrocarbon pool species, and the activity of H-SAPO-34 as a methanol-to-olefins (MTO) catalyst. Successive reaction cycles with different purity feedstocks were studied, with an intermittent regeneration step. The combin...
Article
Full-text available
Incorporation of Ca in ZSM-5 results in a twofold increase of propylene selectivity (53 %), a total light-olefin selectivity of 90 %, and a nine times longer catalyst lifetime (throughput 792 gMeOH gcatalyst−1) in the methanol-to-olefins (MTO) reaction. Analysis of the product distribution and theoretical calculations reveal that post-synthetic mod...
Article
In this Perspective, we highlight the main challenges to be addressed in the development of heterogeneous catalysts for the direct functionalization of methane. Along with our personal view on current developments in this field, we outline the main mechanistic, engineering, and catalyst design issues that have hampered implementation of new technol...
Article
Chabazite zeolites with trimodal porosity (native micropores of CHA framework/additional larger micropores/mesopores) were synthesized by use of a diquarternary ammonium type surfactant C22-4-4 cations and fluoride anions in the synthesis of SSZ-13 zeolite. The fully crystalline hierarchical SSZ-13 zeolites are similar in acidity to bulk SSZ-13 zeo...
Article
The role of water in the methanol-to-olefins (MTO) process over H-SAPO-34 has been elucidated by a combined theoretical and experimental approach, encompassing advanced molecular dynamics simulations and in-situ micro-spectroscopy. First principle calculations at the molecular level point out that water competes with methanol and propene for direct...
Article
Full-text available
A systematic study of the effect of physicochemical properties affecting catalyst deactivation, overall olefin selectivity and ethylene/propylene ratio during the methanol-to-olefins (MTO) reaction is presented for two zeolites with the DDR topology, namely Sigma-1 and ZSM-58. Both catalysts show high selectivity towards light olefins and completel...