XPS studies on a novel amorphous Ni–Co–W–B alloy powder

A novel amorphous Ni–Co–W–B alloy powder, which showed higher catalytic activity than Ni–Co–B for the hydrogenation of benzene, was prepared by chemical reduction and characterized by TEM and XRD. The surface composition and the interactions between the components on the surface were studied by XPS. The measurement detected the presence of some oxides and hydroxides, such as NiO, Ni OH.2, Co OH.2, B2O3 and WO3 associated with their elemental states of Ni, Co, B and W, respectively. The presence of a few number of tungsten atoms leads to more metallic nickel on the surface. q1997 Elsevier Science B.V.