Research progress on performance regulation strategies and mechanisms of ZIF-67-based composite catalysts for hydrogen evolution from water electrolysis

Addressing the key issues of unclear structure-activity relationships and ambiguous active site identification in ZIF-67-based catalysts for the hydrogen evolution reaction （HER） in water electrolysis, this review systematically summarizes the research progress of ZIF-67-based composite catalysts in this field. The crystal structure, pyrolysis transformation behavior, and core advantages of ZIF-67 as a catalyst precursor were first elucidated. Three major modification strategies for enhancing HER performance were then critically analyzed: multi-metal synergistic doping, which optimizes the hydrogen adsorption free energy （ΔG_H*） by modulating the electronic structure; morphology and pore engineering, which increases the exposure of active sites and improves mass transfer through the construction of hollow/hierarchical porous structures; and heterointerface engineering, which enhances reaction kinetics through the construction of synergistic catalytic systems. On this basis, the electrocatalytic performance data of representative ZIF-67-based catalysts in recent years were summarized, and the HER reaction mechanism was discussed in depth. The results indicate that the synergistic effect between Co-Nx sites and cobalt nanoparticles （Co-NPs） is the key to achieving high catalytic activity, as they jointly promote the HER process through electron injection effects and synergistic catalytic pathways. The findings suggest that in-depth understanding of atomic-scale mechanisms, precise regulation of multi-scale structures, and breakthroughs in scalable preparation technologies are the core directions for promoting the industrial application of ZIF-67-based catalysts, providing a theoretical reference for the design of novel non-precious metal electrocatalysts for water electrolysis.