摘要
In this work, we studied the catalytic activity of LaMnO3 and(La0.8A0.2)MnO3(A = Sr, K) perovskite catalysts for oxidation of NO and C10H22 and selective reduction of NO by C10H22. The catalytic per‐formances of these perovskites were compared with that of a 2 wt% Pt/SiO2 catalyst. The La site substitution increased the catalytic properties for NO or C10H22 oxidation compared with the non‐substituted LaMnO3 sample. For the most efficient perovskite catalyst,(La0.8Sr0.2)MnO3, the results showed the presence of two temperature domains for NO adsorption:(1) a domain corre‐sponding to weakly adsorbed NO, desorbing at temperatures lower than 270 °C and(2) a second domain corresponding to NO adsorbed on the surface as nitrate species, desorbing at temperatures higher than 330 °C. For the Sr‐substituted perovskite, the maximum NO2 yield of 80% was observed in the intermediate temperature domain (around 285 °C). In the reactant mixture of NO/C10H22/O2/H2O/He,(La0.8Sr0.2)MnO3 perovskite showed better performance than the 2 wt% Pt/SiO2 catalyst: NO2 yields reaching 50% and 36% at 290 and 370 °C, respectively. This activity improvement was found to be because of atomic scale interactions between the A and B active sites, Sr2+ cation and Mn4+/Mn3+ redox couple. Thus,(La0.8Sr0.2)MnO3 perovskite could be an alternative free noble metal catalyst for exhaust gas after treatment.
In this work, we studied the catalytic activity of LaMnO3 and（La0.8A0.2）MnO3（A = Sr, K） perovskite catalysts for oxidation of NO and C10H22 and selective reduction of NO by C10H22. The catalytic per‐formances of these perovskites were compared with that of a 2 wt% Pt/SiO2 catalyst. The La site substitution increased the catalytic properties for NO or C10H22 oxidation compared with the non‐substituted LaMnO3 sample. For the most efficient perovskite catalyst,（La0.8Sr0.2）MnO3, the results showed the presence of two temperature domains for NO adsorption：（1） a domain corre‐sponding to weakly adsorbed NO, desorbing at temperatures lower than 270 °C and（2） a second domain corresponding to NO adsorbed on the surface as nitrate species, desorbing at temperatures higher than 330 °C. For the Sr‐substituted perovskite, the maximum NO2 yield of 80% was observed in the intermediate temperature domain （around 285 °C）. In the reactant mixture of NO/C10H22/O2/H2O/He,（La0.8Sr0.2）MnO3 perovskite showed better performance than the 2 wt% Pt/SiO2 catalyst： NO2 yields reaching 50% and 36% at 290 and 370 °C, respectively. This activity improvement was found to be because of atomic scale interactions between the A and B active sites, Sr2＋ cation and Mn4＋/Mn3＋ redox couple. Thus,（La0.8Sr0.2）MnO3 perovskite could be an alternative free noble metal catalyst for exhaust gas after treatment.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第8期1299-1304,共6页
基金
Financial supports by national agency for research are gratefully acknowledged.
