Local surface state of amorphous NiP and NiB alloy catalysts

In this work we employ the self-consistent charged-discrete variational Xα (SCC-DV-Xα) to investigate the local surface state of amorphous NiP and NiB alloy, and obtain the following results. Ni is an electron-deficient center, and the d electronic density of Ni atom in NiB increases with metalloid atom contents, and in NiP it increases for low phosphorus contents but decreases for high phosphorus contents. Phosphorus easily gathers on the surface of catalysts with increasing phosphorus contents. The decrease of the pre-exponential factor of ethylene hydrogenation reaction rate on the amorphous alloys is caused by the metalloid atoms segregated to the surface of the catalysts.