【摘要】 以均匀沉淀法制备了超细CeO2/ZnO催化剂,用固定床反应器测试了其对甲烷、二氧化碳氧化偶联反应的催化性能及使用寿命,使用隧道扫描电子显微镜对其亚微观结构进行观察和拍照,应用盒子维法计算出该催化剂的分维数,并分析了分维数与催化性能的关系。结果显示,在一定范围内,分维数较大,则其催化活性较高,但选择性并无规律性变化。分维数可以较真实地表征催化剂表面的几何特性,而不能全面反映其它表面特性。更多还原

【Abstract】 Super fine CeO 2/ZnO catalysts were prepared by homogeneous precipitation under different conditions.The catalytic performance in the oxidative coupling reaction of methane with carbon dioxide in a fixed bed reactor was investigated.The fractal behaviors of the catalysts were analyzed using fractal theory with the aid of SEM technology.It was found that within a certain range,the bigger the values of fractal dimension,the higher conversion of methane will be.However,the same relation was not found in C 2 selectivity,which should be connected with the electronic characteristics of catalysts.Respecting carbon deposition of the catalyst,the fractal dimension also did not show any specific relationship.Thus it seems the fractal theory should be used together with other measures to reflect in a comprehensive manner the characteristics of the catalyst.更多还原