Engineering Elongated Cu─O─Co Bridges at Heterojunction Interfaces for Efficient Photocatalytic CO 2 ‐to‐C 2 H 4 Conversion

ABSTRACT The photocatalytic conversion of CO 2 into high‐value C 2 products presents a promising green route toward renewable energy storage, fine chemical production and carbon neutrality. However, this process is limited so far by the high energy barrier for C─C coupling and the low efficiency of intermediate protonation. In this study, we constructed a 3hCuO/(Cu 0.7 Co 0.3 )Co 2 O 4 heterojunction photocatalyst and identified the formation of elongated interfacial Cu─O─Co bridging bonds. This catalyst delivers a record‐high C 2 H 4 production rate of 211.5 µmol g −1 h −1 in a CO 2 /water vapor system under 300 W Xenon lamp illumination, a 7.8‐fold improvement over the control sample. Mechanistic studies indicate that the elongated Cu─O─Co bridges strengthen the synergy between the Cu and Co dual‐metal sites: not only can this structural feature leave room for *CO migration, which facilitates proton transfer to Cu sites and accelerates the rate‐determining step (*CO → *COH), it also mitigates steric hindrance caused by the accumulation of reaction intermediates, thus promoting asymmetric *COH‐CO coupling. Consequently, both the yield and selectivity of C 2 H 4 are significantly enhanced. By offering atomic‐level insights into the bimetallic cooperative catalysis, this work paves the way for the rational design of heterojunction bridging structures to efficiently steer CO 2 reduction pathways toward C 2 and beyond.