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UV-Raman spectroscopy was used to study the molecular structures of TiO2 or ZrO2-supported vana-dium oxide catalysts.The real time reaction status of soot combustion over these catalysts was de-tected by in-situ UV-Raman spectroscopy.The results indicate that TiO2 undergoes a crystalline phase transformation from anatase to rutile phase with the increasing of reaction temperature.However,no obvious phase transformation process is observed for ZrO2 support.The structures of supported va-nadium oxides also depend on the V loading.The vanadium oxide species supported on TiO2 or ZrO2 attain monolayer saturation when V loading is equal to 4(4 is the number of V atoms per 100 support metal ions).Interestingly,this loading ratio(V4/TiO2 and V4/ZrO2) gave the best catalytic activities for soot combustion reaction on both supports(TiO2 and ZrO2).The formation of surface oxygen com-plexes(SOC) is verified by in-situ UV Raman spectroscopy and the SOC mainly exist as carboxyl groups during soot combustion.The presence of NO in the reaction gas stream can promote the pro-duction of SOC.
UV-Raman spectroscopy was used to study the molecular structures of TiO2 or ZrO2-supported vana-dium oxide catalysts. The real time reaction status of soot combustion over these catalysts was de-tected by in-situ UV-Raman spectroscopy. that TiO2 undergoes a crystalline phase transformation from anatase to rutile phase with the increasing reaction temperature. However, no obvious phase transformation process is observed for ZrO2 support. The structures of supported va-nadium oxides also depend on the V loading. The vanadium oxide species supported on TiO2 or ZrO2 attained monolayer saturation when V loading is equal to 4 (4 is the number of V atoms per 100 support metal ions) .Interestingly, this loading ratio (V4 / TiO2 and V4 / ZrO2) gave the best catalytic activities for soot combustion reaction on both supports (TiO2 and ZrO2) .The formation of surface oxygen com-plexes (SOC) is verified by in-situ UV Raman spectroscopy and the SOC mainly exist as carboxyl groups during soot co mbustion. The presence of NO in the reaction gas stream can promote the pro-duction of SOC.