Formation and removal of active oxygen species for the non-catalytic CO oxidation on Au/TiO_2 catalysts  

Au/TiO_2催化剂上非催化CO氧化反应中活性氧物种的生成和消除（英文）

作　　者：Daniel Widmann R.Jurgen Behm 

机构地区：[1]乌尔姆大学表面化学与催化研究所,德国乌尔姆D-89081

出　　处：《Chinese Journal of Catalysis》2016年第10期1684-1693,共10页催化学报（英文）

摘　　要：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 ＆#176;C） by CO pulses and its replenishment by O2 pulses at 80 ＆#176;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 calcina‐tion 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.在定量的瞬时产物分析(TAP)反应器中,于80 oC下采用CO脉冲和O_2脉冲补充等方法,研究了高温(400 oC)焙烧的Au/TiO_2催化剂上活性氧物种的移除反应活性,特别是活性氧物种的性质.以往的研究大多关注的是CO催化氧化反应中活性氧物种及其性质,在典型的反应条件下该物种的形成和消除是可逆的;而本研究表明,催化剂直接焙烧后就存在额外的氧物种;该物种对CO氧化反应也具有活性,但其在典型的反应条件下不生成或生成很少.基于此,讨论了Au/Ti O_2催化剂上CO氧化反应的机理,特别是不同活性氧物种的作用.

关 键 词：Titanium dioxide Gold catalysis Carbon monoxide oxidation Reaction mechanism Active oxygen Temporal analysis of products 

分 类 号：O643.36[理学—物理化学]