Selective Catalytic Reduction of NO on Ag, Co and Cu/Al2O3 in Excess Oxygen
富氧条件下Ag、Co和Cu/Al2O3选择性催化还原NO的研究

The catalytic activities of alumina-supported Ag, Co and Cu for selective reduction of NO with propene as reductant in the presence of excess oxygen were investigated. The catalytic performances of single-component catalysts with different metal loadings and of samples prepared by various methods such as mechanical mixing, one-step impregnation, two-step impregnation, etc. were studied. The experimental results showed that the Ag exhibited the highest conversion of NO to N2 (approximately 89% with 2% loading, wt.) among single-component catalysts, the lower was Co, and the lowest was Cu. The sequence of the temperature for the maximum conversion was on the order of Cu < Co < Ag. For Ag catalysts, the activities between samples of identical loadings prepared by one-step and two-step impregnation were almost the same. The activities of mixed samples were not the simple sum of the single-component catalysts. The mixed Ag-Co sample possessed the highest activity (80% above). The activities of the combinatorial samples declined comparatively to some extent. The activities of one-step impregnation samples descended more markedly and the highest conversion was only over 30%.