Surface state, catalytic activity and selectivity of nickel catalysts in hydrogenation reactions. Part 2;.—Surface characterization of Raney nickel and Urushibara nickel catalysts by X-ray photoelectron spectroscopy

Abstract

The X-ray photoelectron spectroscopic study of Raney and Urushibara nickel catalysts activated under various conditions was undertaken to characterize the surface state of the catalysts including the catalysts' structure. Raney nickel catalys contain both oxidized and metallic aluminium in the activated phase. As for Urushibara nickel catalysts digested with acetic acid or sodium hydroxide, metallic and oxidized zinc were observed in the catalyst surface. Based on the X.p.s. peak intensities for the catalysts, the structure of Urushibara nickel catalysts was found to be that of a supported catalyst, whereas Raney nickel catalysts showed X.p.s. features consistent with those expected for skeletal nickel catalysts.