Ampere-Level Glycerol-Assisted Water Electrolysis Enabled by Strong Interfacial Coupled Co@CeO _{2– <i>x</i>} Heterostructured Catalysts

Glycerol-assisted water electrolysis has emerged as one of the most promising strategies for cogenerating clean hydrogen fuel and value-added chemicals. However, developing high-performance electrode materials to accelerate overall reaction kinetics remains challenging under ampere-level condition. Herein, an interface engineering strategy is proposed to construct a heterostructured o-Co@CeO2–x electrocatalyst featuring strong interfacial Co–O–Ce bridge bonds for ampere-level high-efficient glycerol-assisted water electrolysis. Benefiting from enhanced interfacial electronic conductivity and a high density of exposed active sites, the o-Co@CeO2–x catalyst exhibits outstanding catalytic performance in a membrane-electrode assembly electrolyzer, achieving an ampere-level current density of 1000 mA cm–2 at a small voltage of 2.28 V, a high formate Faradaic efficiency exceeding 96%, and a formate yield of 61.79 mg h–1 cm–2 at 100 mA cm–2, along with excellent long-term operational stability over 100 h. In situ spectroscopic analysis reveals that the formation of the heterointerface facilitates the generation of active species and key intermediates, thereby accelerating the overall reaction kinetics. This work provides insight into interface-modulated catalyst design for efficient biomass-assisted hydrogen production.