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Instruments / Technical Area	Publication Details	Published
	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
	Cascade aerobic selective oxidation over contiguous dual catalyst beds in continuous flow Lee J. Durndell , Mark A. Isaacs , Chao'en Li , Christopher Parlett , Karen Wilson , Adam F. Lee Acs Catalysis DOI: 10.1021/acscatal.9b00092 Show Abstract ▼ Abstract: Cascade reactions represent an atom-economical and energy efficient technology by which to reduce the number of manipulations required for chemical manufacturing. Biocatalytic cascades are ubiquitous in nature, however controlling the sequence of interactions between reactant, intermediate(s), and active sites, remains a challenge for chemocatalysis. Here we demonstrate an approach to achieve efficient cascades using chemical catalysts through flow chemistry. Close-coupling of Pd/SBA-15 and Pt/SBA-15 heterogeneous catalysts in a dual bed configuration under continuous flow operation, affords a high single pass yield of 84 % (a 20-fold enhancement over batch operation) and high stability for >14,000 turnovers in the cascade oxidation of cinnamyl alcohol to cinnamic acid, despite both catalysts being individually inactive for this reaction. Judicious ordering of Pd (first bed) and Pt (second bed) catalysts is critical to promote cascade oxidation with respect to undesired hydrogenation and hydrogenolysis; the latter favoured over the reverse bed sequence or a single mixed PdPt reactor bed. The intrinsic catalytic performance of each bed is preserved in the optimal dual bed configuration, enabling quantitative prediction of final product yields for reactants/intermediates whose individual oxidation behaviour is established. Continuous processing using contiguous reactor beds enables plug-and-play design of cascades employing ‘simple’ catalysts.	Apr 2019
B18-Core EXAFS	Solid base catalysed 5-HMF oxidation to 2,5-FDCA over Au/hydrotalcites: fact or fiction? Leandro Ardemani , Giannantonio Cibin , Andrew Dent , Mark A. Isaacs , Georgios Kyriakou , Adam F. Lee , Christopher Parlett , Stephen A. Parry , Karen Wilson Chemical Science 6 (8), 4940 - 4945 DOI: 10.1039/C5SC00854A Diamond Proposal Number(s): [8688] Show Abstract ▼ Abstract: Nanoparticulate gold has emerged as a promising catalyst for diverse mild and efficient selective aerobic oxidations. However, the mechanism of such atom-economical transformations, and synergy with functional supports, remains poorly understood. Alkali-free Mg–Al hydrotalcites are excellent solid base catalysts for the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furan dicarboxylic acid (FDCA), but only in concert with high concentrations of metallic gold nanoparticles. In the absence of soluble base, competitive adsorption between strongly-bound HMF and reactively-formed oxidation intermediates site-blocks gold. Aqueous NaOH dramatically promotes solution phase HMF activation, liberating free gold sites able to activate the alcohol function within the metastable 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) reactive intermediate. Synergistic effects between moderate strength base sites within alkali-free hydrotalcites and high gold surface concentrations can afford highly selective and entirely heterogeneous catalysts for aqueous phase aldehyde and alcohol cascade oxidations pertinent to biomass transformation.	Jun 2015
B18-Core EXAFS	Alumina-grafted SBA-15 as a high performance support for Pd-catalysed cinnamyl alcohol selective oxidation Christopher Parlett , Lee Durndell , Andreia Machado , Giannantonio Cibin , Duncan W. Bruce , Nicole S. Hondow , Karen Wilson , Adam F. Lee Catalysis Today DOI: 10.1016/j.cattod.2013.11.056 Diamond Proposal Number(s): [7668] Show Abstract ▼ Abstract: Ultrathin alumina monolayers grafted onto an ordered mesoporous SBA-15 silica framework afford a composite catalyst support with unique structural properties and surface chemistry. Palladium nanoparticles deposited onto Al-SBA-15 via wet impregnation exhibit the high dispersion and surface oxidation characteristic of pure aluminas, in conjunction with the high active site densities characteristic of thermally stable, high-area mesoporous silicas. This combination confers significant rate enhancements in the aerobic selective oxidation (selox) of cinnamyl alcohol over Pd/Al-SBA-15 compared to mesoporous alumina or silica supports. Operando, liquid-phase XAS highlights the interplay between dissolved oxygen and the oxidation state of palladium nanoparticles dispersed over Al-SBA-15 towards on-stream reduction: ambient pressures of flowing oxygen are sufficient to hinder palladium oxide reduction to metal, enabling a high selox activity to be maintained, whereas rapid PdO reduction and concomitant catalyst deactivation occurs under static oxygen. Selectivity to the desired cinnamaldehyde product mirrors these trends in activity, with flowing oxygen minimising CO cleavage of the cinnamyl alcohol reactant to trans-β-methylstyrene, and of cinnamaldehyde decarbonylation to styrene.	Jan 2014

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