Publications by authors named "Hutchings G"

Atomic-scale changes can significantly impact heterogeneous catalysis, yet their atomic mechanisms are challenging to establish using conventional analysis methods. By using identical location scanning transmission electron microscopy (IL-STEM), which provides quantitative information at the single-particle level, we investigated the mechanisms of atomic evolution of Ru nanoclusters during the ammonia decomposition reaction. Nanometre-sized disordered nanoclusters transform into truncated nano-pyramids with stepped edges, leading to increased hydrogen production from ammonia.

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Propane dehydrogenation (PDH), an important process for propylene synthesis, relies on expensive noble metals or highly toxic oxides as catalysts. In a recent publication, Gong and co-workers report a breakthrough discovery for PDH by introducing a sustainable catalyst composed of titanium oxide overlayers encapsulating nickel nanoparticles, termed Ni@TiO. This innovative catalyst showcases exceptional performance in PDH, exhibiting high propylene selectivity and stability under industrially relevant conditions.

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Article Synopsis
  • Taste and odor significantly impact the quality of drinking water, with geosmin being a key pollutant that imparts earthy flavors, even at low levels.
  • A hybrid two-step process using dielectric barrier discharge (DBD) and metal oxides, particularly alumina, has been tested for the effective removal and degradation of volatile organic compounds like geosmin and TBA in water treatment.
  • Experimental results reveal that alumina can efficiently adsorb and regenerate in the presence of DBD-generated reactive oxygen species, leading to mineralization of adsorbates and maintaining performance across multiple cycles.
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Alkoxycarbonylation reactions are common in the chemical industry, yet process sustainability is limited by the inefficient utilization of CO. In this study, we address this issue and demonstrate that significant improvements can be achieved by adopting a heterogeneously catalyzed process, using a Ru/NbO catalyst. The Ru/NbO catalyst enables the direct synthesis of methyl propionate, a key industrial commodity, with over 98% selectivity from CO, ethylene and methanol, without any ligands or acid/base promoters.

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Obesity and anxiety are morbidities notable for their increased impact on society during the recent COVID-19 pandemic. Understanding the mechanisms governing susceptibility to these conditions will increase our quality of life and resilience to future pandemics. In the current study, we explored the function of a highly conserved regulatory region (BE5.

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ConspectusHydrogen peroxide (HO) for industrial applications is manufactured through an indirect process that relies on the sequential reduction and reoxidation of quinone carriers. While highly effective, production is typically centralized and entails numerous energy-intensive concentration steps. Furthermore, the overhydrogenation of the quinone necessitates periodic replacement, leading to incomplete atom efficiency.

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Article Synopsis
  • Bimetallic catalysts, like Au-Pd, show higher reaction rates than single-metal catalysts, but the reasons for this improvement are not fully understood.
  • Recent research reveals that cooperative redox enhancement in these bimetallic systems boosts catalysis in thermochemical oxidation and connects thermocatalysis with electrocatalysis.
  • We found that the increased activity stems from the electrochemical polarization of different catalytic sites, creating a new operating potential that enhances reaction efficiency, and identified factors that affect this enhancement across various bimetal combinations.
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The selective oxidation of methane to methanol, using HO generated in situ from the elements, has been investigated using a series of ZSM-5-supported AuPd catalysts of varying elemental composition, prepared via a deposition precipitation protocol. The alloying of Pd with Au was found to offer significantly improved efficacy, compared to that observed over monometallic analogues. Complementary studies into catalytic performance toward the direct synthesis and subsequent degradation of HO, under idealized conditions, indicate that methane oxidation efficacy is not directly related to HO production rates, and it is considered that the known ability of Au to promote the release of reactive oxygen species is the underlying cause for the improved performance of the bimetallic catalysts.

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Heterogeneous catalysis is immensely important, providing access to materials essential for the well-being of society, and improved catalysts are continuously required. New catalysts are frequently tested under different conditions making it difficult to determine the best catalyst. Here we describe a general approach to identify the best catalyst using a data set based on all reactions under kinetic control to calculate a set of key performance indicators (KPIs).

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Electrocatalytic oxygen reduction reaction (ORR) has been intensively studied for environmentally benign applications. However, insufficient understanding of ORR 2 e -pathway mechanism at the atomic level inhibits rational design of catalysts with both high activity and selectivity, causing concerns including catalyst degradation due to Fenton reaction or poor efficiency of H O electrosynthesis. Herein we show that the generally accepted ORR electrocatalyst design based on a Sabatier volcano plot argument optimises activity but is unable to account for the 2 e -pathway selectivity.

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The aerobic oxidation of alcohols and aldehydes over supported heterogeneous catalysts can be considered as comprising two complementary and linked processes: dehydrogenation and oxygen reduction. Significant rate enhancements can be observed when these processes are catalyzed by independent active sites, coupled by electron transport between the two catalysts. This effect, termed cooperative redox enhancement (CORE), could significantly influence how researchers approach catalyst design, but a greater understanding of the factors which influence it is required.

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  • The oxygen evolution reaction (OER) is essential for future energy systems focused on water electrolysis, and iridium oxides serve as effective catalysts due to their corrosion resistance.
  • High activity iridium (oxy)hydroxides can change into less effective rutile IrO at high temperatures, influenced by the amount of residual alkali metals present.
  • The study reveals that lithium-intercalated IrO maintains good activity and stability at 500 °C, making it a promising alternative for enhancing catalyst performance in industrial processes related to PEM membrane production.
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The hydrogen-borrowing amination of alcohols is a promising route to produce amines. In this study, experimental parameters involved in the preparation of Pt/CeO catalysts were varied to assess how physicochemical properties influence their performance in such reactions. An amination reaction between cyclopentanol and cyclopentylamine was used as the model reaction for this study.

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We investigate the effect of chlorides on the photocatalytic degradation of phenol by titania polymorphs (anatase and rutile). We demonstrate how solubilised chlorides can affect the hydroxyl radical formation on both polymorphs with an overall effect on their photodegradative activity. Initially, the photocatalytic activity of anatase and rutile for phenol degradation is investigated in both standard water and brines.

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The direct transformation of methane to methanol remains a significant challenge for operation at a larger scale. Central to this challenge is the low reactivity of methane at conditions that can facilitate product recovery. This review discusses the issue through examination of several promising routes to methanol and an evaluation of performance targets that are required to develop the process at scale.

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Catalysis is involved in around 85 % of manufacturing industry and contributes an estimated 25 % to the global domestic product, with the majority of the processes relying on heterogeneous catalysis. Despite the importance in different global segments, the fundamental understanding of heterogeneously catalysed processes lags substantially behind that achieved in other fields. The newly established Max Planck-Cardiff Centre on the Fundamentals of Heterogeneous Catalysis (FUNCAT) targets innovative concepts that could contribute to the scientific developments needed in the research field to achieve net zero greenhouse gas emissions in the chemical industries.

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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 molecule. Monometallic Pd catalysts show poor methanol selectivity, but this is improved through the formation of Pd alloys, with both PdZn and PdGa alloys showing greatly enhanced methanol productivity compared with monometallic Pd/AlO and Pd/TiO catalysts. Catalyst characterisation shows that the 1 : 1 β-PdZn alloy is present in all Zn containing post-reaction samples, including PdZn/GaO, with the PdGa alloy formed for the Pd/GaO sample.

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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 nanoparticles. Using operando X-ray absorption and in situ scanning transmission electron microscopy, we report direct evidence that this process can be reversed by carrying out a facile oxidative treatment, which redisperses the gold nanoparticles and restores catalytic activity.

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Heterogeneous palladium catalysts modified by N-heterocyclic carbenes (NHCs) are shown to be highly effective toward the direct synthesis of hydrogen peroxide (HO), 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 selection of the N-substituent of the NHC it is possible to greatly enhance catalytic performance when compared to the unmodified analogue and reach concentrations of HO rivaling that obtained by state-of-the-art catalysts. The enhanced performance of the modified catalyst, which is retained upon reuse, is attributed to the ability of the NHC to electronically modify Pd speciation.

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The rise in atmospheric CO concentration and the concomitant rise in global surface temperature have prompted massive research effort in designing catalytic routes to utilize CO as a feedstock. Prime among these is the hydrogenation of CO to make methanol, which is a key commodity chemical intermediate, a hydrogen storage molecule, and a possible future fuel for transport sectors that cannot be electrified. Pd/ZnO has been identified as an effective candidate as a catalyst for this reaction, yet there has been no attempt to gain a fundamental understanding of how this catalyst works and more importantly to establish specific design criteria for CO hydrogenation catalysts.

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