Recently, a research team led by Professor Minghua Huang from the College of Materials Science and Engineering at Ocean University of China (OUC) has made significant progress in the field of anion exchange membrane water electrolysis (AEMWEs) for hydrogen production. The related results have been published in the internationally renowned journals Angewandte Chemie International Edition and ACS Nano.
The development of clean and efficient energy conversion technologies, such as water electrolysis for hydrogen production, is a key pathway toward building a green hydrogen economy. AEMWEs have attracted increasing attention due to their advantages in cost-effectiveness and environmental friendliness. However, the hydrogen evolution reaction (HER) at the cathode under alkaline conditions involves additional water dissociation steps and complex transformations of multiple intermediates, resulting in significantly hindered reaction kinetics at high current densities. Conventional strategies that optimize individual steps are insufficient to overcome this bottleneck. Therefore, there is an urgent need to design efficient HER catalysts with synergistic active sites and to systematically understand the coupling mechanisms among elementary reaction steps.
To address this challenge, the research team introduced the concepts of “positive feedback” and “cascade catalysis”, inspired by enzymatic reactions, into electrocatalytic HER systems. They successfully designed a nitrogen-doped carbon-supported catalyst featuring NiRu dual single atoms and alloy clusters (Ni₁Ru₁–NiRu@NC). In this catalyst, atomic Ni and alloyed Ni finely regulate the electronic structure of adjacent Ru atoms, forming a unique structure that contains both electron-deficient Ru sites (Lewis acid centers) and electron-rich Ru sites (Lewis base centers)—thus constructing homogeneous frustrated Lewis pairs (FLPs).
Figure 1. Research on the positive feedback mechanism of catalyst in alkaline hydrogen evolution reaction
These FLPs synergistically enhance HER performance: the acid sites efficiently dissociate water molecules to generate protons, which are rapidly transferred via hydrogen spillover to adjacent base sites, where hydrogen evolution occurs. Meanwhile, the rapid proton consumption at base sites continuously drives water dissociation at acid sites, forming a self-reinforcing positive feedback catalytic cycle. The catalyst exhibits an overpotential of only 246 mV at a high current density of 1.0 A cm⁻², and maintains stable operation for over 800 hours. The assembled electrolyzer operates continuously for more than 1,000 hours at 1.0 A cm⁻², with an ultra-low degradation rate of 0.015 mV h⁻¹. This work, titled “Positive Feedback-Driven NiRu Frustrated Lewis Pairs Catalyst Enables a Self-Reinforcing Catalytic Cycle for Cascade-Coupled Hydrogen Production,” was published in Angewandte Chemie International Edition.
Figure 2. Schematic diagram of hydrogen overflow of a MOF catalyst system for hydrogen evolution reaction in alkaline/neutral media
In addition, the team developed another FLP-based catalyst derived from an amine-functionalized NiRu metal–organic framework (MOF). In this system, amino groups and Ni sites spontaneously form synergistic FLP active centers, significantly promoting water adsorption and dissociation while creating a local acidic microenvironment favorable for proton transfer. Meanwhile, the amino groups electronically modulate adjacent Ru sites, reducing the energy barrier for hydrogen desorption and enabling continuous short-range hydrogen spillover pathways, thereby accelerating hydrogen evolution kinetics. Benefiting from these synergistic effects, the catalyst demonstrates superior activity and durability compared to commercial platinum-based catalysts under industrial current densities. The assembled AEMWE device achieves a low cell voltage of 1.76 V at 0.5 A cm⁻² and a high energy efficiency of 71.2%. The corresponding study, titled “Frustrated Lewis Pairs Enable Continuous Short-Range Hydrogen Spillover for Industrial-Scale Hydrogen Evolution,” was published in ACS Nano.
These findings deepen the understanding of synergistic catalytic mechanisms and structure–performance relationships of FLP catalysts in efficient hydrogen evolution reactions, providing critical theoretical insights and material support for the practical development of AEMWE technology.
This series of studies was supported by the General Program of the National Natural Science Foundation of China, International (Regional) Cooperation and Exchange Programs, and the Shandong Natural Science Foundation, among others. Ocean University of China is the primary corresponding institution for these works.
Text/Images: Kecheng Tong
Article Links：
https://doi.org/10.1002/anie.202523215
https://doi.org/10.1021/acsnano.5c13246
