【摘要】 研究了以La,Ni氧化物为原料,在高温和氢的气氛下用CaH₂还原制得的LaNi₅,在乙烯加氢反应中的催化性质。发现用此法制备的粉状样品,不需充氢处理和活化,就可以使乙烯在0℃完全转化为乙烷,而且在-78℃也有较高的活性。根据X线衍射,证明此法制得的LaNi₅的体相结构和冶炼法制得的相同;它的高催化活性,XPS能谱和磁性数据,说明在LaNi₅原始表面上有一层活性镍。活性镍的存在,从LaNi₅充氢实验,也得到了进一步证明。因此,此法制得的LaNi₅样品的表面结构和冶炼法不同。更多还原

【Abstract】 Catalytic properties of LaNi5 prepared by reduction method for the hydrogenation of ethylene have been studied. LaNi5 was prepared by reducing the mixture of La oxide and Ni oxide with CaH2 in hydrogen atmosphere at high temperature. It was found that the powder sample of LaNi5 prepared by reduction method could convert the ethylene to ethane completely at 0℃ without any hydrogenation treatment or further activation of the catalyst. X-ray diffraction investigation proved that the bulk structure of LaNi5 prepared by this method was the same as that of LaNi5 by metallurgical method, but its high catalytic activity, XPS spectra, and the data of magnetic susceptibility showed that there was a layer of active nickel on the surface of LaNi5 precursor. The existence of active nickel layer was further proved by the experiments of hydrogenation of LaNi5.For this reason, it may be concluded that the surface structure of LaNi5 prepared by reduction is different from that of LaNi5 prepared by metallurgical method.更多还原