Combined Operando XANES and NMR and ESR Spectroscopies for the Determination of VPO Dynamic States

Abstract Nanoscaled-VPO (vanadium phosphate oxide) catalysts have been prepared on an alumina support with the objective of obtaining crystallites active phase a high surface-to-volume ratio. Since catalysed reaction occurs at surface, these nanoscaled allows studying surface species transformations minimized signal from bulk dominion. The chemical environment and oxidation state has determined by combination NMR, ESR XANES spectroscopies. results allowed to optimize V + P coverage V/P molar ratio minimize concentration isolated vanadium oxide maximize 4+ concentration. distribution phosphorus islands ordered significantly distorted tetra- penta-coordinated aluminium sites catalytic support, thus shaping material optimal structure for desired partial reaction.