Cu掺杂对LaMnO3催化剂的结构和催化氧化性能的影响

采用非晶态多核配合的方法合成了La1-xCuxMnO3(x=0、0.05、0.1、0.2、0.3、0.4、0.5)系列催化剂, 并用X射线衍射(XRD)、透射电镜(TEM)、比表面测定仪(BET)等手段对催化剂的微观结构进行了表征. 研究了Cu掺杂对钙钛矿结构及其对CO催化氧化发光性能及催化氧化CO、CH4性能的影响规律. 结果表明, 当x≤0.1 时, Cu掺杂仍可形成单相的钙钛矿结构; 当x>0.1时, 过量掺杂的Cu以CuO杂相存在. Cu掺杂可改善La1-xCuxMnO3催化剂对CO和CH4的催化氧化活性. 经700 ℃焙烧3 h制备的La0.9Cu0.1MnO3催化剂具有最高CO催化氧化活性(T100%=170 ℃), 该结果与CO催化氧化发光结果一致.而La0.95Cu0.05MnO3催化剂对CH4的催化氧化活性最高(T95%=705 ℃).

Effect of Cu Doping on the Structure and Catalytic Activity of LaMnO3 Catalyst

La1-xCuxMnO3 (x=0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) catalysts were synthesized by amorphous heteronuclear complexingmethod. The catalystswere characterized by XRD, TEM, andN2 adsorption isotherms. The cataluminescence (CTL) response to CO and the activities in the oxidation of CO and CH4 over the catalysts were investigated. XRD analysis indicated that the single-phase perovskite crystals were formed at x≤0.1, but perovskite and CuO phases coexisted at x>0.1. The catalytic activities of La1-xCuxMnO3 catalysts were superior to those of LaMnO3 catalysts for CO oxidation. La0.9Cu0.1MnO3 (calcined at 700 ℃ for 3 h) catalyst showed the highest catalytic activity for CO oxidation (T100%= 170 ℃), which agreed well with the cataluminescence results. However, La0.95Cu0.05MnO3 catalyst showed the highest catalytic activity for CH4 oxidation (T95%=705 ℃).