ausblenden:
Schlagwörter:
vanadium phosphorus oxide (VPO); X-ray absorption spectroscopy (XAS); vanadium L3-edge; n-butane oxidation; electronic structure
14, n-butane oxidation on VPO catalysts
Zusammenfassung:
The surface of an activated vanadium phosphorus oxide (VPO) catalyst was investigated by means of in situ X-ray absorption spectroscopy in the total electron yield mode. We observed significant changes of the V L3-near edge X-ray absorption fine structure (NEXAFS) when the material was transferred from room temperature to working conditions at 400°C in the reaction atmosphere. We studied the same VPO material under different gas compositions comprising the reaction mixture of n-butane and oxygen, pure oxygen and vacuum to elucidate the influence of the gas-surface interaction and the effect of the temperature. The results of this extensive study indicate a dynamic response of the catalyst surface to the applied conditions.