Study of hydrogen evolution reaction on Ni–P amorphous alloy in the light of experimental and quantum chemistry

Abstract

The hydrogen evolution reaction (HER) on Ni–P alloys was investigated experimentally and theoretically. First Ni–P alloys with P content in the range from 5.8 to 10.0 wt% were prepared by electrodeposition. The best catalysis to the HER was found on the Ni–P alloys with P content of 6.0 wt% (10.8 at%). In order to understand the function of P element in Ni–P amorphous alloys for the HER, the density-functional theory (DFT) method and front molecular orbital (FMO) theory were used to analyze the function of P element in Ni–P amorphous alloys for the HER. The research shows: it is easier for water molecule to get the first electron and form Ni n +1–H and Ni n P–H on Ni n +1 clusters than on Ni n P clusters, but it is more difficult for water molecule to get the second electron from Ni n +1–H than Ni n P–H. The strength of Ni n +1–H bond is always greater than that of Ni n P–H. It means it is more difficult for hydrogen evolutes from Ni n +1 clusters than Ni n P clusters. Regardless of which step among all steps of the HER is the rate-control step, the Ni–P alloys with P contents being in a range of 9.1–14.3 at% would be always good to the whole HER.