Au/ZrO_2催化剂在CO氧化反应中的性能

Preparation of Au/ZrO_2 Catalyst and Its Activity in CO Oxidation

采用水溶液沉淀和沉积-沉淀法分别制备了ZrO2载体及相应的Au/ZrO2催化剂,通过CO氧化反应考察了载体的制备条件、催化剂的焙烧温度和预处理温度对催化剂活性的影响;通过X射线衍射、氢程序升温还原(H2-TPR)、X射线光电子能谱(XPS)表征,分析了影响催化剂活性的原因。实验结果表明,载体的制备条件影响催化剂的活性,加入分散剂和微波处理均能提高催化剂的活性;催化剂的预处理条件影响催化剂的性能,催化剂的最佳焙烧温度为250℃,最佳活化温度为100℃。XPS和H2-TPR测试结果表明,Auδ+(0<δ<3,可能是Au+)是催化剂的活性组分。

ZrO2 support and Au/ZrO2 catalyst were prepared by aqueous solution precipitation and deposition- precipitation method, respectively. Effects of support preparation conditions, calcinating temperature and pretreatment conditions of the catalysts on its activity were investigated. The catalytic combustion of CO over the catalyst as probe reaction was conducted to evaluate activity of the catalyst. The catalyst was characterized by means of XRD, XPS and H2 - TPR. Addition of dispersant and use of microwave in support preparation improve catalyst activity. Optimal conditions for catalyst preparation are calcinating temperature 250℃ and pretreatment in air at 100℃. The results of XPS and TPR indicate that Au^δ＋ （0 〈 6 〈 3, perhaps Au^＋） is active species in the catalyst.