In Situ Generation of Pt₂Co₃ Nano‐Alloys in Porous N‐Doped Carbon for Highly Efficient Electrocatalytic Hydrogen Evolution

Abstract

Platinum (Pt) catalysts are the state-of-the-art electrocatalysts for hydrogen evolution reaction (HER), but it is still a challenge to improve the utilization efficiency and stability of Pt-based catalysts. Herein, Pt 2 Co 3 nano-alloys anchored on the surface of the N-doped carbon support are precisely synthesized via metal complex-controlled pyrolysis. Benefiting from the formation and exposure of the bimetallic nano-alloys, the optimal Pt 2 Co 3 / NC-950 electrocatalyst exhibits an extraordinary HER catalytic activity and stability. To achieve a current density of 10 mA cm À 2 , the Pt 2 Co 3 /NC-950 electrocatalyst requires small overpotentials of 12 mV in both acidic and alkaline media with small Tafel slopes of 6 mV dec À 1 and 24 mV dec À 1 in 0.5 M H 2 SO 4 and 1 M KOH, respectively, which is superior to the commercialized Pt/C catalyst. Additionally, the much higher turnover frequencies and the larger electrochemical surface areas of Pt 2 Co 3 /NC-950 further reveal its superior catalytic active sites. Based on theoretical calculations, the outstanding HER activity is found to be attributed to the synergic effect of the Pt and Co components that optimizes the adsorption Gibbs free energy of hydrogen atom and accelerates water dissociation in alkaline media.

PtCu nanoalloy loaded on sulfur-doped porous g-C3N4 for electrocatalytic hydrogen evolution

“…The research shows that alloying can not only reduce the cost 29 but also improve the catalytic activity and stability of Pt. Bing et al 30 use the porous N-doped carbon carrier to load PtCo alloy, which only requires 12 mV overpotential at 10 mA cm −2 under acidic conditions. Theoretical calculation shows that the synergistic effect of Pt and Co reduces the Gibbs free energy of hydrogen adsorption and accelerates the dissociation of water.…”