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Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS	Conversion of glucose to fructose over Sn and Ga-doped zeolite Y in methanol and water media Mohamed M. M. Kashbor , Dedi Sutarma , James Railton , Naoko Sano , Peter J. Cumpson , Diego Gianolio , Giannantonio Cibin , Luke Forster , Carmine D’agostino , Xi Liu , Liwei Chen , Volkan Degirmenci , Marco Conte Applied Catalysis A: General 9 DOI: 10.1016/j.apcata.2022.118689 Diamond Proposal Number(s): [24728] Open Access Show Abstract ▼ Abstract: In this study, we use zeolite Y as a support for the synthesis of Sn and Ga doped zeolites aimed at the isomerization of glucose to fructose. Though these materials are inactive in water, they are active in methanol and we could ascertain a reaction pathway involving a hydride shift for the interconversion of glucose to fructose and mannose, and a Brønsted acid pathway with the formation of a methyl fructoside intermediate and its hydrolysis to fructose if water was added afterwards. By using characterizations comprising: chemisorption, XPS, XRD, HAADF-STEM and EXAFS; it was possible to demonstrate that a straightforward impregnation protocol for the preparation of our catalysts, led to Sn/Y mainly consisting of small SnO2 clusters on the external surface of the zeolite, whereas Ga/Y consisting of highly dispersed Ga species mostly inside the zeolite pores; and a catalytic activity that appears to be dominated by Brønsted acid sites.	May 2022
B18-Core EXAFS	Operando potassium K-edge X-ray absorption spectroscopy: investigating potassium catalysts during soot oxidation Catherine J. Davies , Alexander Mayer , Jess Gabb , Jake M. Walls , Volkan Degirmenci , Paul B. J. Thompson , Giannantonio Cibin , Stan Golunski , Simon Kondrat Physical Chemistry Chemical Physics 173 DOI: 10.1039/D0CP01227K Diamond Proposal Number(s): [19850] Open Access Show Abstract ▼ Abstract: The chemical and structural nature of potassium compounds involved in catalytic soot oxidation have been studied by a combination of temperature programmed oxidation and operando potassium K-edge X-ray absorption spectroscopy experiments. These experiments are the first known operando studies using tender X-rays (∼3.6 keV) under high temperature oxidation reaction conditions. X-ray absorption near edge structure analysis of K2CO3/Al2O3 catalysts during heating shows that, at temperatures between 100 and 200 °C, potassium species undergo a structural change from an initial hydrated K2CO3·xH2O and KHCO3 mixture to well-defined K2CO3. As the catalyst is heated from 200 °C to 600 °C, a feature associated with multiple scattering shifts to lower energy, indicating increased K2CO3 dispersion, due to its mobility at high reaction temperature. This shift was noted to be greater in samples containing soot than in control experiments without soot and can be attributed to enhanced mobility of the K2CO3, due to the interaction between soot and potassium species. No potassium species except K2CO3 could be defined during reactions, which excludes a potential reaction mechanism in which carbonate ions are the active soot-oxidising species. Simulations of K-edge absorption near edge structures were performed to rationalise the observed changes seen. Findings showed that cluster size, unit cell distortions and variation in the distribution of potassium crystallographic sites influenced the simulated spectra of K2CO3. While further simulation studies are required for a more complete understanding, the current results support the hypothesis that changes in the local structure on dispersion can influence the observed spectra. Ex situ characterisation was carried out on the fresh and used catalyst, by X-ray diffraction and X-ray photoelectron spectroscopy, which indicated changes to the carbonate species, in line with the X-ray absorption spectroscopy experiments.	Jul 2020
I11-High Resolution Powder Diffraction	A hydrothermally stable ytterbium metal–organic framework as a bifunctional solid-acid catalyst for glucose conversion David Burnett , Ryan Oozeerally , Ralentri Pertiwi , Thomas W. Chamberlain , Nikolay Cherkasov , Guy J. Clarkson , Yuni K. Krisnandi , Volkan Degirmenci , Richard I. Walton Chemical Communications 316 DOI: 10.1039/C9CC05364F Diamond Proposal Number(s): [13284] Open Access Show Abstract ▼ Abstract: Yb6(BDC)7(OH)4(H2O)4 contains both bridging hydroxyls and metal-coordinated waters, possessing Brønsted and Lewis acid sites. The material crystallises from water at 200 °C. Using the solid as a heterogenous catalyst, glucose is converted into 5-hydroxymethylfurfural, via fructose, with a total selectivity of ∼70% after 24 hours at 140 °C in water alone: the material is recyclable with no loss of crystallinity.	Sep 2019

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