Synergistic Heterostructure Catalyst for Enhanced CO 2 ‐to‐C2 Conversion and High‐Performance Aqueous Zn‐CO 2 Batteries

This study investigates the synergistic interaction of CuO and SnO 2 in a heterostructure catalyst (CuO@SnO 2 ) for the conversion of C1 carbon dioxide (CO 2 ) reduction products to C2 products and its application in high‐performance aqueous Zn‐CO 2 batteries. This synergistic combination enhances the Faradaic efficiency (FE) for ethanol production from 12.5% to 41.8%, shifting the selectivity from C1 to C2 products. The flow‐type aqueous Zn‐CO 2 battery exhibits an ultrahigh power density of 6.5 mW cm −2 , demonstrates a high discharge voltage of 0.9 V, and maintains stable operation over 140 cycles, underscoring the catalyst's exceptional reversibility and durability. During battery discharge, the system achieves a FE of 36.86% for ethanol production. These results highlight the pivotal role of the CuO@SnO 2 synergy in optimizing CO 2 conversion efficiency while generating electrical energy. The findings advance the development of dual‐function energy storage systems that integrate renewable electricity generation with sustainable CO 2 utilization, paving the way for industrial‐scale applications.