【摘要】 采用溶胶-凝胶法制备了孔径分布为50~100 nm的-γAl2O3载体,浸渍法负载助剂CeO2,K2O和MgO.测试了助剂改性的Pd/Al2O3催化剂上CH4催化氧化反应性能.结果表明:助剂提高了Pd/Al2O3催化剂上CH4催化氧化的活性和稳定性.负载20%CeO2催化剂的反应活性与稳定性较好,其转化率达到90%时的反应温度为351℃,转化率达到10%时的反应温度为252℃,相比Pd/Al2O3催化剂分别降低了125℃和118℃.H2-TPR表征结果表明:含有CeO2的催化剂在110~170℃之间出现一个PdO物种的还原峰,PdO还原峰的面积与还原温度分别与催化剂的反应活性相一致.更多还原

【Abstract】 A catalyst support γ-Al2O3 with pore size distribution of 50-100 nm was prepared by a sol-gel method,and promoters CeO2,K2O and MgO were loaded on the support by a dip-molding method.The catalytic activity of the catalysts Pd/Al2O3modified by promoters for CH4 oxidation reaction was investigated.The results show that the catalytic activity and stability of these catalysts were improved.The catalyst loaded with 20% CeO2 is of better catalytic activity and stability.The conversion ratio of CH4 of 90% and 10% were achieved at 351 ℃ and 252 ℃ respectively.Compared with catalyst Pd/Al2O3,the corresponding temperature were decreased by 125℃ and 118℃ respectively while the same conversion ratio of CH4.The results tested by H2-TPR show that only one reduction peak of PdO species on the catalyst appeared at 110-170 ℃.The peak size and the temperature of PdO species reduced by H2 were coincident with the catalytic activity of the catalyst.更多还原