载体对Au-Pd催化剂甲醇部分氧化性能的影响

Effect of supports on activity of Au-Pd catalysts for partial oxidation of methanol

采用沉积沉淀法制备了一系列Au-Pd双金属催化剂,研究了不同载体对Au-Pd双金属催化剂甲醇部分氧化性能的影响,并运用XRD、TPD和TPR等手段对催化剂进行了表征。结果表明,Au-Pd/CeO2催化剂中形成的AuxPdy合金和氧空穴较多,致使Au-Pd/CeO2催化剂的活性较高;CeO2-TiO2和CeO2-ZrO2复合载体较大的比表面积和固溶体的形成有利于H2选择性的提高;Au-Pd/CeO2-ZrO2和Au-Pd/CeO2-TiO2催化剂有较高H2产率的主要原因是H2选择性的提高。

Au-Pd catalysts were prepared by the deposition-precipitation method, and their activities for partial oxidation of methanol were evaluated. XRD, TPR and TPD were used to characterize the catalysts. In comparison to Au-Pd/CeO2-ZrO2 and Au-Pd/CeO2-TiO2 catalysts, the activity of Au-Pd/CeO2 catalyst for partial oxidation of methanol was higher, which can be related to the formation of more AuxPdy alloy and more oxygen vacancies. The hydrogen selectivity of Au-Pd/CeO2 was improved by using additional support （ZrO2 or TiO2）, probably due to a combination of different factors, such as increasing active surface area and dispersion. A higher hydrogen yield was found for Au-Pd/CeO2-ZrO2 and Au-Pd/ CeO2-TiO2 catalysts because of their higher hydrogen selectivity.