David J. Morgan

David J. Morgan
Cardiff University | CU · Cardiff Catalysis Institute

PhD

About

264
Publications
71,426
Reads
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8,932
Citations
Additional affiliations
September 2017 - July 2020
HarwellXPS
Position
  • Manager
Description
  • HarwellXPS is the EPSRC National Facility for X-ray Photoelectron Spectoscopy (XPS). Visit http://www.harwellxps.uk
January 2006 - present
Cardiff University
Position
  • Research Assistant
Education
September 1999 - September 2002
Cardiff University
Field of study
  • Surface Science and Catalysis
September 1996 - July 1999
Cardiff University
Field of study
  • Chemistry

Publications

Publications (264)
Article
Full-text available
Correction for ‘Metal–organic-framework derived Co–Pd bond is preferred over Fe–Pd for reductive upgrading of furfural to tetrahydrofurfuryl alcohol’ by Saikiran Pendem et al. , Dalton Trans. , 2019, 48 , 8791–8802, https://doi.org/10.1039/C9DT01190K.
Article
Supported gold nanoparticles are widely studied catalysts and are among the most active known for the low-temperature water-gas shift reaction, which is essential in fuel and energy applications, but their practical application has been limited by their poor thermal stability. The catalysts deactivate on-stream via the growth of small Au nanopartic...
Article
Full-text available
Heterogeneous palladium catalysts modified by N-heterocyclic carbenes (NHCs) are shown to be highly effective toward the direct synthesis of hydrogen peroxide (H2O2), in the absence of the promoters which are typically required to enhance both activity and selectivity. Catalytic evaluation in a batch regime demonstrated that through careful selecti...
Article
Octadecylphosphonic acid (ODPA) self-assembled monolayers (SAMs) have demonstrated potential for deterring bacterial attachment to titanium, however the coating process is time consuming and uses toxic solvents. In this study, ODPA SAM quantity, quality, and structure were evaluated on titanium quartz crystal microbalance (QCM) sensors by varying s...
Article
Full-text available
Ir/TiO2 catalysts promoted by niobium have been synthesized, characterized by different complementary techniques, and tested for the total oxidation of a set of alkanes and their mixtures. The addition of appropriate amounts of niobium to Ir/TiO2 catalysts resulted in a remarkable increase in the catalytic activity compared to the Nb-free Ir/TiO2 c...
Article
Treatment and subsequent re-use of wastewater from shale gas extraction is a feasible strategy to ensure sustainability and reduce the environmental impact of the process. Here we demonstrate the photocatalytic benefits of improved three-dimensional graphitic carbon nitride (3D g-C3N4) during the degradation of organic contaminants. We show that pr...
Article
The development of robust and reproducible synthetic strategies for the production of carbon dots (CDs) with improved fluorescence quantum yields and distinct emission profiles is of great relevance given the vast range of applications of CDs. The fundamental understanding at a molecular level of their formation mechanism, chemical structure and ho...
Article
Full-text available
Sol immobilization is used to produce bimetallic catalysts with higher activity to monometallic counterparts for a wide range of environmental and commercial catalytic transformations. Analysis of complementary surface characterization (XPS, Boehm's titration, and zeta potential measurements) was used to elucidate alterations in the surface functio...
Article
Full-text available
In oxidation reactions catalysed by supported metal nanoparticles with oxygen as the terminal oxidant, the rate of the oxygen reduction can be a limiting factor. This is exemplified by the oxidative dehydrogenation of alcohols, an important class of reactions with modern commercial applications1-3. Supported gold nanoparticles are highly active for...
Article
Full-text available
The direct synthesis of H 2 O 2 from molecular H 2 and O 2 over Pd-based catalysts, prepared via an industrially relevant, excess chloride co-impregnation procedure is investigated. Initial studies into the well-established PdAu system demonstrated the key role of Pd: Au ratio on catalytic activity, under conditions that have previously been found...
Article
Full-text available
The structural formation of copper molybdate was investigated using a surfactant added during the preparation. The calcined materials were confirmed by XRD to be Cu3Mo2O9 and the absorbance band-gap was calculated to be ca. 2 eV. The addition of surfactant resulted in a platelet morphology, in contrast to the agglomerated particles of the standard...
Article
Full-text available
N 2 O remains a major greenhouse gas and contributor to global warming, therefore developing a catalyst that can decompose N 2 O at low temperatures is of global importance. We have investigated the use of LaSrCoFeO x perovskites for N 2 O decomposition and the effect of surface area, A and B site elements, Co–O bond strength, redox capabilities an...
Article
Full-text available
The direct synthesis of H 2 O 2 from molecular H 2 and O 2 over AuPd catalysts, supported on TiO 2 and prepared via an excess chloride co-impregnation procedure is investigated. The role of Au:Pd ratio on the catalytic activity towards H 2 O 2 formation and its subsequent degradation is evaluated under conditions that have previously been found to...
Article
The introduction of small quantities of tertiary base metals into supported AuPd nanoparticles is found to result in improved catalytic performance towards the direct synthesis of H2O2 compared to the...
Article
The oxidative degradation of organic contaminants via the in-situ synthesis of H2O2 from dilute streams of H2 and O2 has the potential to significantly reduce the detrimental environmental and health...
Article
Selective partial oxidation of methane to valuable oxygenated products remains a great challenge, as typically over oxidation of oxygenated products to COχ is observed. Weak oxidative species on the catalyst...
Article
A number of Pd based materials have been synthesised and evaluated as catalysts for the conversion of carbon dioxide and hydrogen to methanol, a useful platform chemical and hydrogen storage...
Article
Full-text available
The NO and propane oxidation activities of a series of 1%Pt/TiO 2 –SiO 2 catalysts show different underlying trends as the support composition changes. Surface characterisation of the catalysts indicates that the trend for NO conversion is consistent with the oxidation rate being dependent on the degree of metallic character of the Pt nanoparticles...
Article
Full-text available
Surface functional groups have a strong influence on the deposition and final state of nanoparticles adsorbed on to the surface, a role discussed by Professor Spencer in his work. This tribute to Spencer explores the formation of hydroxyls, thiosulfates, sulfites and sulfur atoms on carbon (HOPG) surfaces and their effect on the deposition of gold...
Article
The polymer, poly(diallyldimethylammonium chloride) (PDDA), is shown to undergo chemical change via a reduction mechanism during X-ray analysis. Examination of the N 1s spectrum of PDDA shows a time dependence on the degree of reduction, together with clear amplification of the extent of reduction through the charge compensation system and X-ray ir...
Article
Full-text available
CeO2 catalysts were prepared by a precipitation method using either (NH4)2Ce(NO3)6 or Ce(NO3)3, as CeIV or CeIII precursors respectively. The influence of the different precursors on catalytic activity was evaluated for the total oxidation of propane with water present in the feed. The catalyst prepared using the CeIV precursor was more active for...
Article
The existence of asymmetry in X‐ray photoelectron spectroscopy (XPS) photoemission lines is widely accepted, but line shapes designed to accommodate asymmetry are generally lacking in theoretical justification. In this work, we present a new line shape for describing asymmetry in XPS signals that is based on two facts. First, the most widely known...
Article
Anode materials are key to determining the energy density, cyclability and of life recyclability for Li-ion energy storage systems. High surface area materials, such as MXenes, can be manufactured with improved electrochemical properties that remove the need for polymeric binders or hazardous chemicals that pose a challenge to recycle Li-ion batter...
Article
Gallium arsenide (GaAs) is a promising candidate as a platform for optical biosensing devices due to its enabling optoelectronic properties. However, the biofunctionalisation of the GaAs surface has not received much attention compared to gold, carbon and silicon surfaces. Here we report a study presenting a physicochemical surface characterisation...
Article
Full-text available
X-ray photoelectron spectroscopy (XPS) has achieved maturity as an analytical technique in that it is a ubiquitous tool in the materials community, however as made apparent by recent reviews highlighting it's misuse as a means of chemical deduction, it is a practice which is greatly misunderstood even in its simplest form. Advanced XPS techniques,...
Article
Full-text available
The oxidation of cyclohexane via the in-situ production of H 2 O 2 from molecular H 2 and O 2 offers an attractive route to the current industrial means of producing cyclohexanone and cyclohexanol (KA oil), key materials in the production of Nylon. The in-situ route has the potential to overcome the significant economic and environmental concerns a...
Article
The methodology presented within this work is a result of years of interactions between many junior and senior X-ray Photoelectron Spectroscopy (XPS) users operating within the CasaXPS spectral processing and interpretation program framework. In particular, discussions arising from a series of workshops have been a significant source for developing...
Article
The direct synthesis of hydrogen peroxide from molecular H2 and O2 offers an attractive alternative to the current means of production of this powerful oxidant, on an industrial scale. Herein we investigate the role of nitric acid addition, during catalyst preparation as a means of improving catalytic performance, under reaction conditions that hav...
Article
A series of TiO2anatase materials were synthesized with varying proportions of exposed (101) and (001) facets. Pt was subsequently impregnated onto these materials, which were then exposed to either an aerobic or reductive thermal treatment. The final catalysts were assessed for their performance in the aerobic, solvent free oxidation of octanol. M...
Article
Full-text available
The surface chemistry of carbon materials is predominantly explored using x-ray photoelectron spectroscopy (XPS). However, many published papers have critical failures in the published analysis, stemming from an ill-informed approach to analyzing the spectroscopic data. Herein, a discussion on lineshapes and changes in the spectral envelope of pred...
Article
Full-text available
Globally, water disinfection is reliant on chlorination, but requires a route that avoids the formation of chemical residues. Hydrogen peroxide, a broad-spectrum biocide, can offer such an alternative, but is typically less effective than traditional approaches to water remediation. Here, we show that the reactive oxygen species—which include hydro...
Article
X-ray Photoelectron Spectroscopy of large bandgap or insulating material surfaces relies on an effective mechanism that compensates for the emission (loss) of electrons by maintaining the material surface at a steady-state uniform potential. While a steady-state may be attained by utilizing an active compensation, such as low power electron emittin...
Preprint
div>We report a study presenting a physicochemical surface characterisation of the GaAs surface along the functionalisation with a high-affinity bioconjugation pair widely explored in the life sciences: biotin and neutravidin. Combined X-ray photoelectron spectroscopy (XPS), wettability measurements and spectroscopic ellipsometry were used for a r...
Article
X-ray photoelectron spectroscopy (XPS) was used to characterize a graphitic carbon nitride (g-C3N4) sample synthesized by the high temperature treatment of urea. Core-level C(1s) and N(1s) spectra are presented to aid fitting of such materials and address inconsistencies noted within published research literature.
Article
Full-text available
Ternary lanthanide indium oxides LnInO3 (Ln = La, Pr, Nd, Sm) were synthesized by high-temperature solid-state reaction and characterized by X-ray powder diffraction. Rietveld refinement of the powder patterns showed the LnInO3 materials to be orthorhombic perovskites belonging to the space group Pnma, based on almost-regular InO6 octahedra and hig...
Article
Full-text available
Bimetallic Pd-Fe catalysts supported on TiO2 are shown to be highly effective toward the selective oxidation of benzyl alcohol to benzaldehyde via the in situ production of H2O2 from molecular H2 and O2, under conditions where no reaction is observed with molecular O2 alone. The rate of benzyl alcohol oxidation observed over supported Pd-Fe nanopar...
Article
Glucose, a readily available biomass precursor is used for the production of carbon quantum dots (CQDs) via a fast, efficient, and environmentally benign continuous hydrothermal flow synthesis (CHFS) process using supercritical water, an approach that can readily be scaled up for industrialization, producing materials with enhanced properties. The...
Article
Full-text available
Increasing carbon dioxide (CO2) emissions, resulting in climate change, have driven the motivation to achieve the effective and sustainable conversion of CO2 into useful chemicals and fuels. Taking inspiration from biological processes, synthetic iron-nickel-sulfides have been proposed as suitable catalysts for the hydrogenation of CO2. In order to...
Article
Full-text available
The oxidation of cyclohexane via the in-situ production of H2O2 from molecular H2 and O2 offers an attractive route to the current industrial means of producing cyclohexanone and cyclohexanol (KA oil), both key materials in the production of Nylon. Herein we demonstrate that through the in-situ production of H2O2 supported AuPd nanoparticles cataly...
Article
Full-text available
Low temperature oxidation of alcohols over heterogeneous catalysts is exceptionally challenging, particularly under neutral conditions. Herein, we report on an efficient, base-free method to oxidise glycerol over a 0.5%Pd-0.5%Fe/SiO 2 catalyst at ambient temperature in the presence of gaseous H 2 and O 2 . The exceptional catalytic performance was...
Article
The combination of heterogeneous catalysis and biocatalysis into one-pot reaction cascades is a potential approach to integrate enzymatic transformations into existing chemical infrastructure. Peroxygenases, which can achieve clean C-H activation,...
Article
A new oleophobic composite material was synthesised utilising multi-layered graphitic (MLG) material as scaffolding is presented herein. The composite consisted of a polyelectrolyte/fluorosurfactant complex derived from polydiallyldimethylammonium chloride (PDDA) and...
Article
The oxidative degradation of phenol via the in-situ production of H2O2 from molecular H2 and O2 offers an attractive route to the destruction of organic contaminants in water streams, potentially...
Article
Selective partial oxidation of methane to methanol under ambient conditions is a great challenge in chemistry. Iron modified ZSM-5 catalysts are shown to be effective for this reaction using H2O2...
Article
Controlling the selectivity of a reaction by rational designing of catalyst is an exciting and an important topic in catalysis research. In this article, we report a strategy to control the selectivity during the aqueous phase hydrogenolysis of glycerol using gaseous H 2 . Ru/TiO 2 is an active catalyst for the hydrogenolysis of glycerol, however i...
Article
Full-text available
A range of Cs-doped Fe/Al2O3 catalysts were prepared for the ammonia decomposition reaction. Through time on-line studies it was shown that at all loadings of Cs investigated the activity of the Fe/Al2O3 catalysts was enhanced, with the optimum Cs:Fe being ca. 1. Initially, the rate of NH3 decomposition was low, typically < 10% equilibrium conversi...
Article
Full-text available
We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument ge...
Article
Catalytic total oxidation of noxious volatile organic compounds (VOCs) is an important process to remove these compounds from the atmosphere. This is the first systematic study of the influence of the support on the activity of iridium oxide supported catalysts for the total oxidation of VOCs. Iridium catalysts supported on titania, γ-alumina, sili...
Article
Full-text available
Rapidly increasing anthropogenic carbon dioxide (CO2) emissions, coupled with irreversible climate change and depleting fossil fuels reserves, has significantly increased the drive for CO2 utilization. Iron sulfide as a catalyst for the hydrogenation of CO2 has been discussed in the literature for decades, especially in an origin-of-life context, h...
Article
A novel radical-based functionalisation strategy for the synthesis of functionalised commercially obtained plasma-synthesised multi-layer graphitic material (MLG) is presented herein. 4-(trifluoromethyl)phenyl boronic acid was utilised as a source of 4-(trifluoromethyl)phenyl radicals to covalently graft upon the graphitic surface of MLG. Such a me...
Article
Full-text available
A series of Pt-based catalysts were synthesised and investigated for ambient temperature CO oxidation with the aim to increase catalytic activity and improve moisture resistance through support modification. Initially, bimetallic PtPd catalysts supported on alumina were found to exhibit superior catalytic activity compared with their monometallic c...
Article
The direct synthesis of hydrogen peroxide (H2O2) has been studied using a solvent system comprising a hydrophobic alcohol (decan-1-ol) and water. It is demonstrated that, with the optimum combination of solvent and catalyst the contribution of H2O2 degradation pathways can be minimised to achieve industrially acceptable H2O2 concentrations under mo...
Article
Full-text available
The reactivity of AuPd nanoparticle catalysts prepared by sol immobilisation is often explained by a structure activity relationship based solely on particle size or composition. In this contribution, we compare colloidal AuPd nanoparticles stabilised with polyvinylpyrolidone (PVP) with the same AuPd nanoparticles supported on TiO2 for the direct s...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Currently, there is a paucity in the exploration and application of carbon-based nanomaterials for enhanced oil recovery. Carbon quantum dots (CQDs), 0D materials consisting of a graphitic core covered by an amorphous carbon framework, were produced from glucose +/- a dopant molecule (p-sulfonic acid calix[4]arenes) via Continuous Hydrothermal Flow...
Article
Pt/KL is the widely accepted catalyst for aromatizing n-hexane by 1,6 ring closure but encounters deactivation issues when aromatizing higher carbon-number feeds; undergoing extensive dealkylation to give unwanted CH4 and unselective products, as well as over-aromatization to form coke. Here, we report the use of a non-acidic MFI zeolite support, c...
Article
The introduction of small quantities of Pt into supported AuPd nanoparticles is found to result in enhanced catalytic efficiency in the direct synthesis of H2O2. This is attributed to a combination of superior H2O2 synthesis rates, as determined through calculation of initial rates of reaction, and an inhibition of H2O2 degradation pathways, achiev...