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Instruments / Technical Area	Publication Details	Published	Actions
I11-High Resolution Powder Diffraction	Molecular understanding of the catalytic consequence of ketene intermediates under confinement Wei Chen , Guangchao Li , Xianfeng Yi , Sarah J. Day , Karolina A. Tarach , Zhiqiang Liu , Shang-Bin Liu , Shik Chi Edman Tsang , Kinga Góra-Marek , Anmin Zheng Journal Of The American Chemical Society DOI: 10.1021/jacs.1c08036 Open Access Show Abstract ▼ Abstract: Neutral ketene is a crucial intermediate during zeolite carbonylation reactions. In this work, the roles of ketene and its derivates (viz., acylium ion and surface acetyl) associated with direct C–C bond coupling during the carbonylation reaction have been theoretically investigated under realistic reaction conditions and further validated by synchrotron radiation X-ray diffraction (SR-XRD) and Fourier transformed infrared (FT-IR) studies. It has been demonstrated that the zeolite confinement effect has significant influence on the formation, stability, and further transformation of ketene. Thus, the evolution and the role of reactive and inhibitive intermediates depend strongly on the framework structure and pore architecture of the zeolite catalysts. Inside side pockets of mordenite (MOR), rapid protonation of ketene occurs to form a metastable acylium ion exclusively, which is favorable toward methyl acetate (MA) and acetic acid (AcOH) formation. By contrast, in 12MR channels of MOR, a relatively longer lifetime was observed for ketene, which tends to accelerate deactivation of zeolite due to coke formation by the dimerization of ketene and further dissociation to diene and alkyne. Thus, we resolve, for the first time, a long-standing debate regarding the genuine role of ketene in zeolite catalysis. It is a paradigm to demonstrate the confinement effect on the formation, fate, and catalytic consequence of the active intermediates in zeolite catalysis.	Sep 2021
B18-Core EXAFS	Catalytic decomposition of N2O over Cu–Al–Ox mixed metal oxides Magdalena Jablonska , Miren Agote Arán , Andrew M. Beale , Kinga Góra-Marek , Gérard Delahay , Carolina Petitto , Kateřina Pacultová , Regina Palkovits Rsc Advances 9, 3979 - 3986 DOI: 10.1039/C8RA10509J Diamond Proposal Number(s): [14834] Open Access Show Abstract ▼ Abstract: Cu–Al–Ox mixed metal oxides with intended molar ratios of Cu/Al = 85/15, 78/22, 75/25, 60/30, were prepared by thermal decomposition of precursors at 600 °C and tested for the decomposition of nitrous oxide (deN2O). Techniques such as XRD, ICP-MS, N2 physisorption, O2-TPD, H2-TPR, in situ FT-IR and XAFS were used to characterize the obtained materials. Physico-chemical characterization revealed the formation of mixed metal oxides characterized by different specific surface area and thus, different surface oxygen default sites. The O2-TPD results gained for Cu–Al–Ox mixed metal oxides conform closely to the catalytic reaction data. In situ FT-IR studies allowed detecting the form of Cu+⋯N2 complexes due to the adsorption of nitrogen, i.e. the product in the reaction between N2O and copper lattice oxygen. On the other hand, mostly nitrate species and NO were detected but those species were attributed to the residue from catalyst synthesis.	Jan 2019

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