Nano‐Confined Carbon Channels Enable Efficient Acidic CO 2 Electrolysis to Ethylene
Xilei Ding, Jianhui Wang, Shijie Yang, Min Wang, Zixu Wang, Deen Li, Dongke Li, Qingyuan Hao, Zehui Zhang, Sung‐Fu Hung, Guangbin Zhang, Zhongwei Yu, Jun Xu, Hucheng SongABSTRACT
Acidic electrochemical CO 2 reduction reaction (CO 2 RR) offers a promising route for carbon utilization by mitigating carbonate formation that commonly occurs in alkaline and neutral electrolytes. However, efficient CO 2 ‐to‐C 2 H 4 conversion under strongly acidic conditions remains challenging because copper‐based catalysts suffer from severe corrosion and competitive hydrogen evolution reaction (HER). Herein, we report a nano‐confined‐channel‐modified copper catalyst fabricated through flash Joule heating‐driven rapid pyrolysis of waste polypropylene. The resulting graphitized carbon forms abundant nanoscale confined channels on the copper surface, creating a protective and microenvironment‐regulating interface that suppresses catalyst corrosion while maintaining accessible Cu active sites. As a result, the catalyst achieves a C 2 H 4 Faradaic efficiency of 70% at 400 mA cm − 2 , while sustaining a total C 2 Faradaic efficiency exceeding 80% over 200–700 mA cm − 2 . Molecular dynamics simulations and in situ characterizations reveal that the nano‐confined carbon interface promotes local K + accumulation, enriches reaction intermediates, and establishes a locally high‐pH microenvironment, thereby suppressing the HER and favoring C─C coupling during acidic CO 2 RR conditions. This work highlights nano‐confined carbon channels as an effective interfacial engineering strategy for acid‐tolerant CO 2 RR and provides a sustainable pathway for upcycling waste plastics into functional carbon modifiers for efficient CO 2 ‐to‐C 2 H 4 conversion.