合成甲醇铜系催化剂前体物相的研究

Study on phase composition in the precursor of a Cu based methanol synthesis catalyst

用ＸＲＤ研究了负载型铜系催化剂前体中碱式碳酸盐物相以及在沉淀过程中形成活性物相的条件，并寻找前体物相的结构与混合氧化物催化性能的关系。与传统共沉淀法相比，它除了具有共同的水滑石、孔雀石、水锌矿外，还生成有Ｃｕ、Ｚｎ共晶的单斜绿铜锌矿（ｒｏｓａｓｉｔｅ）。由于Ｃｕ、Ｚｎ共晶，使得在反应合成甲醇时，能更好地发挥Ｃｕ、Ｚｎ间的协同作用，更有利于合成反应的进行，其反应活性较一步共沉淀提高１０％。

Phase composition of subcarbonate in the precursor of a supported Cu based catalyst and conditions for forming the subcarbonate during precipitation were studied by using XRD technique.The relation between the phase structure in the precursor and catalytic properties of the mixed oxide was also investigated.It was found that a rosasite with an eutectic structure of Cu and Zn had formed in the precursor of the present catalyst besides the same hydrotalcite,malachite and hydrojincite as those formed by the traditional coprecipitation method.Because of Cu Zn eutectic,the synergy between Cu and Zn during synthetic reaction is believed to be stronger,thus more favourable to methanol synthesis.The activity of the supported Cu based catalyst prepared by the present method increases by 10% compared with that of the catalyst by one step coprecipitation,and the optimum reaction temperature decreases by 20℃。