Synthesis of Ni3 B/Ni via Vacuum-Induced for Ultrahigh Stable and Efficient Methanol Oxidation.

ABSTRACT

Designing efficient catalysts to promote the electrochemical oxidation of anodes is the core of the development of electrochemical synthesis technologies, such as HER and CO2 RR. Here, a novel vacuum induction strategy is used to synthesize nickel boride/nickel (Ni3 B/Ni) heterostructure catalyst for electrochemical oxidation of methanol into formic acid. The catalyst has extremely high reactivity (only 146.9 mV overpotential at 10 mA cm-2 , the maximum current density reaches 555.70 mA mg-1 and 443.87 mA cm-2 ), ultra-high selectivity (Faraday efficiency of methanol conversion to formic acid is close to 100%), and ultra-long life (over 50 h at 100 mA cm-2 ). In-suit electrochemical impedance spectroscopy proved that MeOH is oxidized first and inhibits the phase transition of the electrocatalyst to the high-valent electrooxidation products, which not only enables the high selectivity of MeOH oxidation but also ensures high stability of the catalyst. The mechanism studies by density functional theory calculations show that the potential determining step, the formation of *CH2 O, occurs most favorably in the Ni3 B/Ni heterostructure. These results provide references for the development of MeOH oxidation catalysts with high activity, high stability, high selectivity, and low cost.