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 thes...
详细信息
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.
自然材料中的非线性响应本质上是弱的，有效的光频混频通常必须在较长的相互作用长度上积累。相位匹配的需求限制了混合过程的效率。来自伦敦帝国学院的Rupert F. Oulton团队报道了在硅基电信波长下微米尺度相互作用长度的高效四波混合...
详细信息
自然材料中的非线性响应本质上是弱的，有效的光频混频通常必须在较长的相互作用长度上积累。相位匹配的需求限制了混合过程的效率。来自伦敦帝国学院的Rupert F. Oulton团队报道了在硅基电信波长下微米尺度相互作用长度的高效四波混合技术（FWM），采用一个将光强烈限制在非线性有机聚合物中的集成等离子体缝隙波导，将光压缩到一个只有25nm宽的通道中。
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