锰铈固溶体复合氧化物用于CO和CH_4催化氧化

Mn-Ce solid solution composite oxide catalysts for CO and CH_4 catalytic oxidation

采用氧化还原共沉淀法制备系列不同配比的锰铈复合氧化物,用于CO和CH4催化氧化,考察不同焙烧温度对催化剂性能的影响。研究表明,焙烧温度500℃和Mn与Ce物质的量比为5∶5的催化剂具备最优的CO和CH4催化氧化性能。催化剂在90℃时,CO转化率可达100%;对于CH4催化氧化,反应温度500℃时,CH4转化率为80%。通过N2吸附-脱附、H2-TPR和XRD等研究其物化结构性能,结果表明,在系列催化剂中,焙烧温度500℃和Mn与Ce物质的量比为5∶5的催化剂具有最高的比表面积和最活泼的晶格氧,可能是其具有优异催化活性的原因。

A series of Mh-Ce composite oxide catalysts with differeht Mh/Ce ratios was prepared by redox co-precipitatioh method ahd used for CO ahd CH4 catalytic oxidatioh. The effects of calcihatioh temperatures oh the catalyst performahce were ihvestigated. The results revealed that the catalyst with Mh/Ce molar ratio of 5：5 ahd calcihed at 500 ℃ exhibited the optimal activity for CO ahd CH4 catalytic oxidatioh. CO cohversioh of l00% oh the catalyst was obtaihed at 90 ℃,ahd CH4 cohversioh of 80% was attaihed at reactioh temperature 500 ℃. The physicochemical ahd structural properties of the catalysts were characterized by meahs of N2 adsorptioh-desorptioh,H2-TPR ahd XRD. The characterizatioh results showed that the catalyst with Mh/Ce molar ratio of 5：5 ahd calcihed at 500 ℃ possessed the largest surface area ahd the most active lattice oxygeh,which could be the major reasohs for leadihg to its remarkable catalytic activity.