Conversion of novel bimetallic metal organic frameworks into hierarchically structured electrocatalysts for high performance hydrogen evolution

Abstract

Developing economically viable and high-performance electrocatalysts for the hydrogen evolution reaction (HER) is crucial for achieving sustainable hydrogen production. However, achieving a combination of high catalytic activity and long-term stability remains a challenge. In this study, we report the development of hierarchically porous hollow Co–Ni doped carbon electrocatalysts synthesized via pyrolysis. The optimized CoNi-MOF@850 °C catalyst exhibited excellent HER kinetics in alkaline media, requiring only 148 mV overpotential at 10 mA cm⁻² with a Tafel slope of 65 mV dec⁻¹, surpassing the monometallic Co and Ni catalysts and approaching the performance of the commercial Pt/C (95 mV, 43 mV dec⁻¹). Notably, when employed in an AEM electrolyzer, the CoNi-MOF@850 °C catalyst maintained ∼96% potential retention over 100 h at 200 mA cm⁻², demonstrating an exceptional stability. The synergistic interaction between Co and Ni, combined with the hierarchical porous structure, enhances electronic conductivity, increases active site density, and facilitates efficient charge transfer, leading to the observed superior catalytic performance. These results demonstrate the potential of bimetallic MOF-derived catalysts as cost-effective and sustainable alternatives to noble-metal-based electrocatalysts for large-scale green hydrogen production technologies.