Probing the electronic structure of NiX, (X = B, S, P) catalysts with XPS

Amorphous films of NiB, NiP and NiS were produced by electrodeposition on pure polycrystalline Ni. The films were studied with X‐ray photoelectron spectroscopy (XPS). Changes in the Auger parameter (AP), peak energy shifts and changes in the Ni 2p shake up satellite intensity and energy were used to probe the electronic changes occurring upon alloying Ni with P, S and B. It is suggested that the Ni sites experience a higher electron density in the alloys than in the pure element and this could be the reason for the increased catalytic activity.