Bimetallic MOF-based catalysts with enhanced activity for electrochemical hydrogen evolution in acid and alkaline electrolytes

Abstract

A family of MOF-based bimetallic electrocatalysts MxNi1-x-NKU-100 (M = Mn, Fe, Co, Cu, Zn) are synthesized for hydrogen evolution reaction (HER). The modulcation of the bimetallic centers signeficantly influence the electrocatalytic HER activities. In acidic electrolyte, the CuxNi1-x-NKU-100 exhibits superior electrocatalytic performance. Cu0.22Ni0.78-NKU-100 achieved 10 mA cm-2 current density at 224 mV overpotential with a 126 mV dec-1 Tafel slope. In alkaline electrolytes, the FexNi1-x-NKU-100 catalysts exhibit better electrocatalytic HER activities compared with other MxNi1-x-NKU-100. Fe0.24Ni0.76-NKU-100 achieved 10 mA cm-2 current density at 249 mV overpotential with a Tafel slope of 137 mV dec-1. The synergistic effects of the bimetallic electrocatalysts in acidic and alkaline electrolytes were discussed in detail.