Preparation of Pt/Co(OH)2–NiO/C catalysts and their electrocatalytic oxidation of methanol

Abstract

Novel Pt/Co(OH)₂–NiO/C catalysts based on carbon black were successfully synthesized using the hydrazine hydrate reduction method and galvanic replacement strategies. They were subsequently tested for their activity in the electrocatalytic oxidation of methanol. It was observed that the peak current density of Pt/Co(OH)₂–NiO/C (8.29 A mg_Pt⁻¹) was 22.4 times higher than that of commercial Pt/C-JM (0.37 A mg_Pt⁻¹). The electrocatalytic activities and durabilities of the synchronously synthesized Pt/Co(OH)₂–NiO/C catalysts were significantly better than those of PtCo/C, PtNi/C, and PtCoNi/C-X (X = 200, 400, 600) catalysts synthesized by calcination in Ar at different temperatures. The reason is that the highly dispersed Pt helps to expose more active sites on the catalyst surface, and the addition of Co(OH)₂ and NiO alters the electron density of Pt, which reduces the adsorption of intermediate CO, attenuates the toxic effect, and enables more efficient oxidation of methanol.