Building zero-carbon industrial parks has been encouraged, aiming to accelerate the country's green transition. There is an urgent need for efficient and clean energy conversion technologies. Water electrolysis for hydrogen production serves as a crucial technological path for electricity-hydrogen-chemical coupling. Its performance heavily relies on the structural design and interface regulation of electrocatalytic materials.

In a study published in Angewandte Chemie International Edition, a research team led by Prof. ZHAO Shenlong from the National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences proposed a novel strategy coupling anodic formaldehyde (HCHO) oxidation with water electrolysis, enabling the co-production of green hydrogen and high-value chemicals.

Researchers developed a computation-guided strategy—localized hydrogen-affinity engineering—to synthesize Rh-decorated Cu hydrogenase single-atom alloy catalyst (Rh₁Cu-Hase). This catalyst achieved a remarkable Faraday efficiency of > 99.3% for formaldehyde conversion at an ultrahigh current density of 500 mA cm⁻² with a minimal overpotential of 283 mV, significantly outperforming electrocatalytic materials.

In a coupled membrane-free electrolyzer system, the single-atom alloy catalyst was able to be operated stably for over 1200 hours at an industrial-level current density of 1000 mA cm^-2, enabling bipolar hydrogen production and continuous synthesis of high-purity potassium diformate. The energy consumption for hydrogen production was reduced to as low as 0.63 kWh Nm⁻³, demonstrating excellent potential for industrial application.

Operando characterizations, comparative experiments and theoretical calculations revealed a Rh-Cu host-guest dual-site synergistic catalytic mechanism: paired dehydrogenation mechanism. The Cu matrix facilitated the adsorption of aldehyde intermediates, while the atomic Rh sites promoted electrocatalytic C-H bond cleavage and H-H coupling. This synergy accelerated multi-electron transfer and proton-coupled kinetics, achieving a match between anodic oxidation and cathodic hydrogen evolution.

The universality of this catalyst was demonstrated by its application in electrifying the oxidation of a broad range of industrially relevant aldehydes. This study demonstrates a feasible route for coupled anodic oxidation and water electrolysis, and offers new insights into the precise design of high-performance nanocatalysts.