Ester hydrogenolysis over promoted Cu/SiO2 catalysts

A series of Cu/SiO2 catalysts promoted with manganese, iron, cobalt, nickel , molybdenum, magnesium and yttrium was prepared by homogeneous deposition precipitation. For most catalysts a copper metal surface of about 15 m(2) g (-1) catalyst is measured. TPR reveals that copper-promoter contact is good for most samples. Despite similar Cu-0 surface areas, ester hydrogenolysis activity varies considerably with the type of promoter, in the following o rder: Mo>Co greater than or equal to Zn greater than or equal to Mn>Fe grea ter than or equal to Y>Ni>>Mg. As a function of metal-oxygen bond strength, a vulcano type catalyst activity plot is observed. With respect to alkanes formation, a correlation with normalised electronegativity is observed, in ferring that the formation of alkanes proceeds on Lewis acid sites, which i s in agreement with literature results. When both activity and selectivity are taken into account, manganese and zinc are the promoters of choice. (C) 1999 Elsevier Science B.V. All rights reserved.