为了避免柠檬酸溶胶-凝胶法制备过程中环境问题,采用共沉淀法制备了Cu-Mn-Ce复合氧化物催化剂,以催化燃烧甲苯为模型反应,考察了沉淀剂对Cu-Mn-Ce催化结构和性能的影响。结果表明,以Na OH作为沉淀剂催化剂效果最佳,其次为NH3·H2O、K2CO3、Na2C2O4。采用Na OH作为沉淀剂,氢氧化物前体在焙烧活化过程中更易使Cu、Mn离子进入Ce O2的立方结构,形成具有缺陷结构的Ce O2固溶体,从而提高了表面氧浓度和活动性,在燃烧反应中表现出更优异的催化特性。
Cu-Mn-Ce(CMC) ternary mixed oxides were prepared by the co-precipitation method with different precipitants, and evaluated in catalytic combustion of toluene. The catalyst prepared with Na OH(CMC-Na OH)exhibited the highest catalytic activity, followed by the catalyst prepared with NH3?H2O, K2CO3, and Na2C2O4. The precursors of hydroxide derived from Na OH had strong interaction, and Cu, Mn ions more easily entered the lattice of Ce O2 fluorite structure to form Ce O2 solid solution during calcination. As a result, the structure containing Cu-Mn mixed oxides and Ce O2 solid solution enhanced the mobility of active oxygen owing to abundant defective sites on the surface, which benefited catalytic combustion of toluene.