负载型金催化剂的制备及其性能研究

Preparation of Support Gold Catalyst and Its Catalytic Performance

采用水溶液沉淀法制备了MgO/CeO2混合载体,并采用沉积-沉淀法制备了相应Au/MgO/CeO2催化剂,以CO氧化反应作为表征反应,考察了载体的结构对催化剂性能的影响,并对催化剂进行了AAS、XRD、XPS和TPR表征,分析了影响催化剂活性的原因。实验结果表明:载体的结构对催化剂的活性有一定影响,CeO2显著提高催化剂的活性,MgO对催化剂活性的影响不明显;XPS和TPR测试结果表明,催化剂中均含有氧化态的金,并且和催化剂活性相关,说明Auδ(+0<δ<3)是催化剂的活性相组分。

Aqueous precipitation and deposition-precipitation method were used to prepare the composite oxide MgO/CeO2 supports and Au/MgO/CeO2 catalysts respectively. The effect of structure of supports on the catalyst activity was investigated. The catalytic combustion of CO was taken as the probe reaction for comparing the catalyst activity. AAS, XRD, XPS and TPR were carried out to analyze the influence factor on the catalysts activity. Results indicated that the catalytic activity was affected by the structure of supports, CeO2 showed higher performance than MgO for improving the catalytic activity. Result of XPS and TPR indicated that the catalysts contained the oxidized gold and the Au^2＋（0〈δ〈3,perhaps Au^1＋） species was catalytic activity component.