Studies of supported nickel catalysts by X-ray photoelectron and ion scattering spectroscopies

Studies of supported nickel catalysts by X-ray photoelectron and ion scattering spectroscopies provided evidence that nickel does not interact with a silica support but forms nickel monoxide; that on ..gamma..-alumina, low nickel contents form two nickel species which interact with the support, of which one is in tetrahedral alumina sites and difficult to reduce and the other, in octahedral sites and easy to reduce; that at higher calcination temperatures, nickel in octahadral sites diffuses to tetrahadral sites; and that higher nickel loadings on ..gamma..-alumina, nickel monoxide forms on top of the interacting nickel species. The studies were performed with 2-33.2Vertical Bar3< nickel on ..gamma..-alumina and 4-35Vertical Bar3< nickel on silica, prepared by impregnation with nickel nitrate and calcined at 400/sup 0/-600/sup 0/C.