Abstract
Electrochemical energy conversion and storage through hydrogen has revolutionized sustainable energy systems using fuel cells and electrolyzers. Regrettably, the sluggish alkaline hydrogen oxidation reaction (HOR) hampers advances in fuel cells. Herein, we report a Pt/Ni3N-Mo2C bifunctional electrocatalyst toward HOR and hydrogen evolution reaction (HER). The Pt/Ni3N-Mo2C exhibits remarkable HOR/HER performance in alkaline media. The mass activity at 50 mV and exchange current density of HOR are 5.1 and 1.5 times that of commercial Pt/C, respectively. Moreover, it possesses an impressive HER activity with an overpotential of 11 mV @ 10 mA cm(-2), which is lower than that of Pt/C and most reported electrocatalysts under the same conditions. Density functional theory (DFT) calculations combined with experimental results reveal that Pt/Ni3N-Mo2C not only possesses an optimal balance between hydrogen binding energy (HBE) and OH- adsorption but also facilitates water adsorption and dissociation on the catalyst surface, which contribute to the excellent HOR/HER performance. Thus, this work may guide bifunctional HOR/HER catalyst design in the conversion and transport of energy.