Electroshock synthesis of a bifunctional nonprecious multi‐element alloy for alkaline hydrogen oxidation and evolution
Lijie Du, Xiong Hu, Hongcheng Lu, Li‐Ming Yang, Rong‐Zhen Liao, Bao Yu Xia, Bo You
Abstract
Abstract The design and production of active, durable, and nonprecious electrocatalysts toward alkaline hydrogen oxidation and evolution reactions (HOR/HER) are extremely appealing for the implementation of hydrogen economy, but remain challenging. Here, we report a facile electric shock synthesis of an efficient, stable, and inexpensive NiCoCuMoW multi‐element alloy on Ni foam (NiCoCuMoW) as a bifunctional electrocatalyst for both HOR and HER. For the HOR, the current density of NiCoCuMoW could reach ∼11.2 mA cm –2 when the overpotential is 100 mV, higher than that for commercial Pt/C (∼7.2 mA cm –2 ) and control alloy samples with less elements, along with superior CO tolerance. Moreover, for the HER, the overpotential at 10 mA cm −2 for NiCoCuMoW is only 21 mV, along with a Tafel slope of low to 63.7 mV dec −1 , rivaling the commercial Pt/C as well (35 mV and 109.7 mV dec −1 ). Density functional theory calculations indicate that alloying Ni, Co, Cu, Mo, and W can tune the electronic structure of individual metals and provide multiple active sites to optimize the hydrogen and hydroxyl intermediates adsorption, collaboratively resulting in enhanced electrocatalytic activity.