Synthesis of Mo2C-based material in DC arc discharge plasma under ambient air conditions

Abstract

Molybdenum carbide is a well-known material, which properties makes it good candidate for replacing platinum in hydrogen production by electrolysis. Mo2C phase shows the best characteristics among other molybdenum carbide phases in HER. In this paper Mo2C-based powder material has been synthesized by non-vacuum DC arc discharge method. The main advantage of the method is the synthesis under ambient air conditions, which leads to low cost and more effectiveness of the process. We carried out several series of experiments to determine the optimal synthesis parameters that ensure the dominance of the Mo2C phase in the synthesis product. Carbon nanofibers (CNFs) obtained via catalytic pyrolysis of ethylene on Ni–Cu alloy were used as a carbon source. CNFs were characterized by SEM and low-temperature adsorption/desorption of N2. According to XRD analysis, the optimal ratio of the initial components C:Mo is 1:16 wt, arc current is 200 A, and plasma exposure time is 30 s. In this paper, for the first time the oxidation behavior of the Mo2C-based material, obtained in DC arc discharge plasma under ambient air conditions, was investigated by TG/DTA. The noble metal free HER electrocatalyst with the synthesized material as precursor was prepared for investigation of electrocatalytic activity.