In-situ UV-Raman study on soot combustion over TiO2 or ZrO2-supported vanadium oxide catalysts

• 来源期刊: 中国科学B辑（英文版）
• 年，卷（期）: 2008,（6）
• 页码范围: 551-561
• 页数: 11页
• 语种: 英文
• DOI: 10.1007/s11426-008-0027-2

摘要

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 TiO= undergoes a crystalline phase transformation from anatase to futile 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.