Constructing Hollow Structures and Coordination Defects in ZIF-8 Through a Uniquely Gas-Phase Etching Strategy to Achieve Efficient CO 2 -to-CO Conversion Across a Wide Potential Range

The electrocatalytic reduction of carbon dioxide to carbon monoxide represents an ideal pathway for sustainable carbon cycling; nevertheless, developing electrocatalysts that maintain high selectivity across a broad potential window remains a formidable challenge. In this work, we developed a novel ZIF-8-based catalyst with hollow structures and coordination defects via a uniquely gas-phase etching strategy, achieving high-selectivity CO generation across a wide potential range that surpasses all previously reported crystalline ZIF-8 catalysts. The constructed hierarchical porous hollow structure substantially increases specific surface area and mass transport efficiency. Concurrently, etching-induced coordination defects modulate the electronic structure of Zn–N 4 sites, effectively lowering the energy barrier for forming the key *COOH intermediate and promoting *CO desorption. The E 60 -ZIF-8 catalyst exhibits a CO Faradaic Efficiency (FE CO ) of over 93% within the voltage range of −0.8 V to −1.6 V (vs RHE). It reaches its peak value of 96.6% at −1.4 V (vs RHE). This work provides novel insights and approaches for designing high-performance electrocatalysts.