甲烷部分氧化反应Ni-CeO_2模压催化剂的研究

采用机械混合法和溶液浸渍法两种不同方式向Ni金属催化剂中添加CeO2助剂,制备了甲烷部分氧化制合成气反应用Ni-CeO2催化剂。以SEM、XRD和TPR等方法对催化剂进行了表征,并采用常压微型反应器对催化剂活性进行了评价。结果表明,与用机械混合法制备的催化剂相比,用溶液浸渍法制备的Ni-CeO2催化剂中CeO2晶粒更细小、分散更均匀,催化剂具有均匀的网状结构,其催化甲烷部分氧化性能也较佳。与不加助剂的纯Ni基模压催化剂相比,用溶液浸渍法制备的Ni-CeO2催化剂的氧化还原性发生了变化,其TPR耗氢峰向低温方向移动,将w(CeO2)=10%的Ni-CeO2催化剂用于甲烷部分氧化反应时,得到了较高的甲烷转化率及氢气和一氧化碳选择性。

Study on Molded Ni-CeO2 Catalysts for the Partial Oxidation of Methane

The CeO2 doped Ni-based molded catalysts(Ni-CeO2)for the partial oxidation of methane to syngas were prepared by two different methods of mechanical mixing and wetness impregnation.The catalysts were characterized by SEM,XRD and TPR,and the POM activities of the catalysts were evaluated on the normal pressure microreactor system.The results showed that the Ni-CeO2 catalyst prepared by impregnation method has smaller size of ceria crystallites,more homogeneous textural characteristics and thus better catalytic POM performance compared with those prepared by mechanical mixing method.The TPR test showed that the main reduction peak of nickel species is shifted to lower temperature after CeO2 addition,thus the redox properties of Ni-CeO2 catalyst is improved.When the Ni-CeO2 catalyst with 10wt% CeO2 content was used to partial oxidation of methane to syngas,it showed higher CH4 conversion,also H2 selectivity and CO selectivity.