低浓度CH_4燃烧催化剂制备及其反应性能研究

Study on preparation and reaction performance of catalyst to CH_4 combustion in low concentration

采用化学共沉淀-凝胶工艺制备纳米γ-Al_2O_3载体,氧化钾(K_2O)、氧化镁(MgO)、氧化铈(CeO_2)为催化助剂,PdO为催化剂活性组分,浸渍法负载催化剂组分。研究了活化升温速率、助剂种类及助剂加入方式对催化剂性能的影响。结果表明,富氧气氛下经缓慢氧化活化后的催化剂表现出较高的活性;浸渍法添加助剂的催化剂活性高于共沉淀法加入助剂的催化剂;助剂K_2O、MgO和CeO_2均能够提高催化剂活性,除K_2O外,催化剂活性随着助剂的含量增加而增大,其中20%CeO_2的催化剂表现出较高的催化活性。

The γ-Al2O3 was used as support prepared by chemical eoprecipitation -gel method, and the components of catalyst were loaded on the support through impregnation, as well the K2O, MgO and CeO2 as catalytic promoter, PdO as the active component, the catalyzer to combustion CH4 of low concentration were be made and investigated the effect of heating rate of activation, the species and adding ways of additive. The results showed that the higher activation could be obtained in excess oxygen with low speed of oxidation; it presented upper activation with the method of impregnation to rather than co-precipitation; the adding of K2O,MgO and CeO2 could improve the activity of the catalyst, and the more content of adding, the higher activity showed except K2O, while the activity got higher with 20% CeO2 catalyst.