Issue
Korean Journal of Chemical Engineering,
Vol.24, No.3, 503-507, 2007
Influences of A- or B-site substitution on the activity of LaMnO3 perovskite-type catalyst in oxidation of diesel particle
LaMnO3 was partially substituted at A- or B-site by Sol-Gel method and characterized by XRD, SEM and BET. Perovskite oxides were formed in all substitutions. The catalytic activities of substituted catalysts on carbon black oxidation were measured by Temperature Programming Oxidation (TPO). Experimental results showed that all substitutions increased the catalytic activity of LaMnO3, and La0.8Cs0.2MnO3 showed the highest catalytic activity. Under tight contact, the activity enhancement of different substitutions decreased in the order Cs>K>V>Ce>Co>Cu>Fe. Dynamic analysis showed that partial substitutions increased the pre-exponential factor and the catalytic activity by increasing the oxygen vacancy on the catalyst surface. The active components on the surfaces of La0.8Ce0.2MnO3 and LaMn0.8V0.2O3 included CeO2 and LaVO4, which changed the apparent activities and dynamic parameters of these two catalysts.