Nature-Inspired Strategies for Designing Proton-Relay Pathways in Water-Splitting Catalysts

Abstract

Electrochemical water splitting (EWS), a sustainable pathway for green hydrogen production, faces critical industrial challenges: insufficient activity and stability at high current densities, reliance on scarce noble metals, and unresolved kinetic bottlenecks in proton-coupled electron transfer (PCET) dynamics. Natural metalloenzymes drive water splitting at exceptionally low overpotentials via precisely coordinated proton-coupled electron transfer (PCET) pathways within their active sites, achieving efficiencies approaching the theoretical thermodynamic potential of the reaction (1.23 V vs. RHE), thereby offering transformative design principles for synthetic catalysts. This review begins by analyzing the structural motifs and catalytic mechanisms of natural metalloenzymes involved in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with a particular focus on their PCET-driven reaction dynamics. Subsequently, we summarize the inspiring strategies derived from the design of the natural enzyme active sites and their ligand environments, highlighting their relevance to HER and OER catalyst development. In conclusion, we advocate for a multiscale, nature-inspired catalyst design paradigm that integrates deep learning, high-throughput computation, and cutting-edge in situ characterization to systematically understand and optimize intrinsic activity (overpotential), stability, and reaction pathway (selectivity), thereby achieving synergistic design from atomic-scale active sites to macroscopic system architectures. These nature-inspired strategies could bridge the gap between enzymatic precision and industrial scalability, unlocking EWS technologies with enzyme-like efficiency and durability.

Keywords

Nature-inspired strategies / Proton-coupled electron transfer / Hydrogen evolution reaction / Oxygen evolution reaction

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