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Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS	Palladium-doped hierarchical ZSM-5 for catalytic selective oxidation of allylic and benzylic alcohols Shengzhe Ding , Muhammad Ganesh , Yilai Jiao , Xiaoxia Ou , Mark Isaacs , Mark S'Ari , Antonio Torres Lopez , Xiaolei Fan , Christopher M. A. Parlett Royal Society Open Science 8 DOI: 10.1098/rsos.211086 Diamond Proposal Number(s): [15151] Open Access Show Abstract ▼ Abstract: Hierarchical zeolites have the potential to provide a breakthrough in transport limitation, which hinders pristine microporous zeolites and thus may broaden their range of applications. We have explored the use of Pd-doped hierarchical ZSM-5 zeolites for aerobic selective oxidation (selox) of cinnamyl alcohol and benzyl alcohol to their corresponding aldehydes. Hierarchical ZSM-5 with differing acidity (H-form and Na-form) were employed and compared with two microporous ZSM-5 equivalents. Characterization of the four catalysts by X-ray diffraction, nitrogen porosimetry, NH3 temperature-programmed desorption, CO chemisorption, high-resolution scanning transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy allowed investigation of their porosity, acidity, as well as Pd active sites. The incorporation of complementary mesoporosity, within the hierarchical zeolites, enhances both active site dispersion and PdO active site generation. Likewise, alcohol conversion was also improved with the presence of secondary mesoporosity, while strong Brønsted acidity, present solely within the H-form systems, negatively impacted overall selectivity through undesirable self-etherification. Therefore, tuning support porosity and acidity alongside active site dispersion is paramount for optimal aldehyde production.	Oct 2021
I18-Microfocus Spectroscopy	Study of the mechanism of nucleation of platinum nanoparticles through X-ray absorption spectroscopy using a continuous flow microfluidic device Sylvia Britto , Christopher Parlett , Stuart Bartlett , Konstantin Ignatyev , Sven L. Schroeder XAFS2021 Show Abstract ▼ Abstract: Platinum nanoparticles exhibit unique catalytic properties and have a number of important applications: as an industrial catalyst for fuel cells, in the synthesis of nitric acid, as well as in the reduction of exhaust gases from vehicles. While there have been many studies demonstrating size and morphology control of platinum nanoparticles, a molecular level understanding of the nucleation and growth mechanisms underlying nanoparticle formation, which is crucial for efficient optimization of size controlled synthesis, is lacking in the literature. Structurally incisive experimental in situ probes with enough spatial and temporal resolution are needed to monitor nucleation and growth processes. Here we use operando X-ray Absorption Spectroscopy (XAS) coupled with continuous flow microfluidics to study the mechanisms of platinum nanoparticle formation by reduction of H2PtCl6 using ethylene glycol as a reducing agent. In contrast to a batch synthesis, a continuous flow device allows for rapid and efficient mixing of precursors and fine control over the synthesis parameters such as concentration, flow rate and temperature. The XAS results capture the intermediate stages of nanoparticle formation through to complete reduction to Pt nanoparticles. The setup described here can, in principle, be used to study nanoparticle nucleation and growth mechanisms of a wide range of nanoparticles that occur at fast (microsecond) timescales.	Jul 2021
	Recent developments in multifunctional catalysts for fatty acid hydrodeoxygenation as a route towards biofuels Shengzhe Ding , Christopher M. A. Parlett , Xiaolei Fan Molecular Catalysis 42 DOI: 10.1016/j.mcat.2021.111492 Show Abstract ▼ Abstract: Catalytic hydrodeoxygenation (HDO) provides a promising route for upgrading biomass-derived fatty acids to alkanes, which are potential biofuels (e.g. jet fuel (C8–C16) and diesel (C12–C22)) that could reduce our reliance on unsustainable fossil fuels. Currently, catalytic HDO, conducted over catalysts such as molybdenum disulfide, necessitates harsh operating conditions (>300 °C) which is both environmentally and economically unsustainable and promotes unwanted side reactions, e.g. cracking, which compromises product selectivity. Accordingly, the development of novel catalysts, which enable efficient and sustainable HDO, under milder operating conditions, and their translation from lab bench to large-scale production are highly desired. This review discusses the recent development of heterogeneous catalysts for HDO (including reaction pathways, mechanisms, and side reactions) and explores design strategies for the development of new multifunctional catalysts with potential to enable future development of HDO processes under mild conditions. In particular, we consider the sequential cascade transformation of fatty acids into fatty alcohols (via hydrodeoxygenation) and then hydrocarbons (via dehydration and hydrogenation), which requires the coupling of different but complementary catalytic sites, as an attractive alternative mild HDO strategy.	Mar 2021
I11-High Resolution Powder Diffraction I20-EDE-Energy Dispersive EXAFS (EDE)	Control of zeolite microenvironment for propene synthesis from methanol Longfei Lin , Mengtian Fan , Alena M. Sheveleva , Xue Han , Zhimou Tang , Joseph H. Carter , Ivan Da Silva , Christopher Parlett , Floriana Tuna , Eric J. L. Mcinnes , German Sastre , Svemir Rudic , Hamish Cavaye , Stewart F. Parker , Yongqiang Cheng , Luke L. Daemen , Anibal J. Ramirez-Cuesta , Martin P. Attfield , Yueming Liu , Chiu C. Tang , Buxing Han , Sihai Yang Nature Communications 12 DOI: 10.1038/s41467-021-21062-1 Diamond Proposal Number(s): [2359] Open Access Show Abstract ▼ Abstract: Optimising the balance between propene selectivity, propene/ethene ratio and catalytic stability and unravelling the explicit mechanism on formation of the first carbon–carbon bond are challenging goals of great importance in state-of-the-art methanol-to-olefin (MTO) research. We report a strategy to finely control the nature of active sites within the pores of commercial MFI-zeolites by incorporating tantalum(V) and aluminium(III) centres into the framework. The resultant TaAlS-1 zeolite exhibits simultaneously remarkable propene selectivity (51%), propene/ethene ratio (8.3) and catalytic stability (>50 h) at full methanol conversion. In situ synchrotron X-ray powder diffraction, X-ray absorption spectroscopy and inelastic neutron scattering coupled with DFT calculations reveal that the first carbon–carbon bond is formed between an activated methanol molecule and a trimethyloxonium intermediate. The unprecedented cooperativity between tantalum(V) and Brønsted acid sites creates an optimal microenvironment for efficient conversion of methanol and thus greatly promotes the application of zeolites in the sustainable manufacturing of light olefins.	Feb 2021
	Atom efficient PtCu bimetallic catalysts and ultra dilute alloys for the selective hydrogenation of furfural Martin J. Taylor , Simon K. Beaumont , Mohammed J. Islam , Sotirios Tsatsos , Christopher A. M. Parlett , Mark A. Isaacs , Georgios Kyriakou Applied Catalysis B: Environmental DOI: 10.1016/j.apcatb.2020.119737 Show Abstract ▼ Abstract: A range of Pt:Cu bimetallic nanoparticles were investigated for the liquid-phase selective hydrogenation of furfural, an important platform biomass feedstock. Alloying of the two metals had a profound effect on the overall catalytic activity, providing superior rates of reaction and achieving the needed high selectivity towards furfuryl alcohol. Furthermore, we investigated the catalytic activity of an Ultra Dilute Alloy (UDA) formed via the galvanic replacement of Cu atoms by Pt atoms on dispersed host Cu nanoparticles (atomic ratio Pt:Cu 1:20). This UDA, after overcoming an induction period, exhibits exceptionally high initial rates of hydrogenation under modest hydrogen pressures of 10 and 20 bar, rivalling the catalytic turnover for the monometallic Pt (containing 12 times more Pt), and outdoing the pure Cu or other compositions of bimetallic nanoparticle alloy catalysts. These atom efficient catalysts are ideal candidates for the valorization of furfural due to their activity and vastly greater economic viability.	Nov 2020
	Shining light on the solid–liquid interface: in situ / operando monitoring of surface catalysis Leila Negahdar , Christopher M. A. Parlett , Mark A. Isaacs , Andrew M. Beale , Karen Wilson , Adam F. Lee Catalysis Science & Technology 10, 5362 - 5385 DOI: 10.1039/D0CY00555J Open Access Show Abstract ▼ Abstract: Many industrially important chemical transformations occur at the interface between a solid catalyst and liquid reactants, despite which relatively little attention has been paid to spectroscopic methods for interrogating the working solid–liquid interface. This partly reflects a limited number of analytical techniques that give access to interface-specific information. Direct observation of surface species at catalytic solid–liquid interfaces is a daunting challenge for many in situ techniques due to the low concentration and/or short lifetime of chemical species in dynamic reactions. This review discusses the application of in situ and operando spectroscopies to probe solid–liquid interfaces, with a focus on the resulting mechanistic insight in the context of catalysis for sustainable chemistry.	Aug 2020
	Metal–acid synergy: Hydrodeoxygenation of anisole over Pt/Al‐SBA‐15 Atal Shivhare , James A. Hunns , Lee J. Durndell , Christopher M. A. Parlett , Mark A. Isaacs , Adam F. Lee , Karen Wilson Chemsuschem 2013 DOI: 10.1002/cssc.202000764 Show Abstract ▼ Abstract: Hydrodeoxygenation (HDO) is a promising technology to upgrade fast pyrolysis bio‐oils but it requires active and selective catalysts. Here we explore the synergy between the metal and acid sites in the HDO of anisole, a model pyrolysis bio‐oil compound, over mono‐ and bi‐functional Pt/(Al)‐SBA‐15 catalysts. Ring hydrogenation of anisole to methoxycyclohexane occurs over metal sites and is structure sensitive; it is favored over small (4 nm) Pt nanoparticles, which confer a turnover frequency (TOF) of approximately 2000 h−1 and a methoxycyclohexane selectivity of approximately 90 % at 200 °C and 20 bar H2; in contrast, the formation of benzene and the desired cyclohexane product appears to be structure insensitive. The introduction of acidity to the SBA‐15 support promotes the demethyoxylation of the methoxycyclohexane intermediate, which increases the selectivity to cyclohexane from 15 to 92 % and the cyclohexane productivity by two orders of magnitude (from 15 to 6500 mmol gPt−1 h−1). Optimization of the metal–acid synergy confers an 865‐fold increase in the cyclohexane production per gram of Pt and a 28‐fold reduction in precious metal loading. These findings demonstrate that tuning the metal–acid synergy provides a strategy to direct complex catalytic reaction networks and minimize precious metal use in the production of bio‐fuels.	Jun 2020
	Ethanol steam reforming for hydrogen production over hierarchical macroporous mesoporous SBA-15 supported nickel nanoparticles Christopher M. A. Parlett , Lee J. Durndell , Mark A. Isaacs , Xiaotong Liu , Chunfei Wu Topics In Catalysis 63, 403 - 412 DOI: 10.1007/s11244-020-01265-4 Open Access Show Abstract ▼ Abstract: The influence of complementary macropores, present in hierarchical macroporous mesoporous SBA-15, on the performance of supported Ni nanoparticles for ethanol steam reforming has been investigated. The increased open nature of the architecture, afforded through the incorporation of the secondary macropore network, enables superior metal dispersion. This, in turn, enhances catalytic hydrogen production performance through the generation of a greater density of active sites.	May 2020
B18-Core EXAFS	The effect of metal precursor on copper phase dispersion and nanoparticle formation for the catalytic transformations of furfural Mohammed J. Islam , Marta Granollersmesa , Amin Osatiashtiani , Martin J. Taylor , Jinesh C. Manayil , Christopher M. A. Parlett , Mark A. Isaacs , Georgios Kyriakou Applied Catalysis B: Environmental DOI: 10.1016/j.apcatb.2020.119062 Show Abstract ▼ Abstract: The formation of copper-based catalysts ranging from nanoparticles to isolated and dimeric Cu species supported on nanophased alumina is reported and utilised for the catalytic liquid-phase hydrogenation of furfural. The materials were synthesised via wet impregnation using various copper precursors (nitrate, acetate and sulphate) at two different loadings. A high Cu loading (5 wt%) led to the formation of well-defined nanoparticles, while a lower loading (1 wt%) generated a highly dispersed phase consisting mostly of atomic and dimeric Cu species dispersed on Al2O3. The catalytic reaction was found to be structure sensitive, promoting decarbonylation reactions with low Cu loading. Copper sulphate derived catalysts were found to severely decrease furfuryl alcohol selectivity from 94.6% to 0.8%, promoting the formation of side reactions. The sulphur-free catalysts represent a greener and more sustainable alternative to the toxic catalysts currently used in industry, operating at milder conditions of 50 °C and 1.5 bar H2.	Apr 2020
B18-Core EXAFS I11-High Resolution Powder Diffraction	Quantitative production of butenes from biomass-derived γ-valerolactone catalysed by hetero-atomic MFI zeolite Longfei Lin , Alena M. Sheveleva , Ivan Da Silva , Christopher M. A. Parlett , Zhimou Tang , Yueming Liu , Mengtian Fan , Xue Han , Joseph H. Carter , Floriana Tuna , Eric J. L. Mcinnes , Yongqiang Cheng , Luke L. Daemen , Svemir Rudic , Anibal J. Ramirez-Cuesta , Chiu C. Tang , Sihai Yang Nature Materials 19, 86 - 93 DOI: 10.1038/s41563-019-0562-6 Diamond Proposal Number(s): [15151, 24726] Show Abstract ▼ Abstract: The efficient production of light olefins from renewable biomass is a vital and challenging target to achieve future sustainable chemical processes. Here we report a hetero-atomic MFI-type zeolite (NbAlS-1), over which aqueous solutions of γ-valerolactone (GVL), obtained from biomass-derived carbohydrates, can be quantitatively converted into butenes with a yield of >99% at ambient pressure under continuous flow conditions. NbAlS-1 incorporates simultaneously niobium(v) and aluminium(iii) centres into the framework and thus has a desirable distribution of Lewis and Brønsted acid sites with optimal strength. Synchrotron X-ray diffraction and absorption spectroscopy show that there is cooperativity between Nb(v) and the Brønsted acid sites on the confined adsorption of GVL, whereas the catalytic mechanism for the conversion of the confined GVL into butenes is revealed by in situ inelastic neutron scattering, coupled with modelling. This study offers a prospect for the sustainable production of butene as a platform chemical for the manufacture of renewable materials.	Dec 2019

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