Formation and removal of active oxygen species for the non-catalytic CO oxidation on Au/TiO₂ catalysts

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• 作者：Daniel Widmann ; R. Jü ; rgen Behm ; ^{juergen.behm@uni-ulm.de" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Titanium dioxide ; Gold catalysis ; Carbon monoxide oxidation ; Reaction mechanism ; Active oxygen ; Temporal analysis of products
• 刊名：Chinese Journal of Catalysis
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：37
• 期：10
• 页码：1684-1693
• 全文大小：759 K

文摘

Applying quantitative temporal analysis of products reactor measurements, we studied the reactive removal of active oxygen present on Au/TiO₂ catalysts after calcination at elevated temperatures (400 °C) by CO pulses and its replenishment by O₂ pulses at 80 °C, focusing on the nature of the active oxygen species. In contrast to previous studies, which mainly focused on and clarified the nature of the active oxygen species for the catalytic CO oxidation, which is reversibly formed and replenished under typical reaction conditions, this study demonstrates that directly after calcination an additional oxygen species is present. This species is also active for the CO oxidation, but it is not or only very little formed under typical reaction conditions. Implications of these results on the mechanistic understanding of the CO oxidation on Au/TiO₂, in particular on the role of different active oxygen species, will be discussed.