External fields are introduced to catalytic processes to improve catalytic activities. The light field effect plays an important role in electrocatalytic processes, but is not fully understood. Here we report a series of photo-coupled electrocatalysts for CO₂ reduction by mimicking the structure of chlorophyll. The porphyrin-Au catalyst exhibits a high turnover frequency of 37,069 h⁻¹ at −1.1 V and CO Faradaic efficiency (FE) of 94.2% at −0.9 V. Under visible light, the electrocatalyst reaches similar turnover frequency and FE with potential reduced by ~ 130 mV. Interestingly, the light-induced positive shifts of 20, 100, and 130 mV for porphyrin-Co, porphyrin-Cu, and porphyrin-Au electrocatalysts are consistent with their energy gaps of 0, 1.5, and 1.7 eV, respectively, suggesting the porphyrin not only serves as a ligand but also as a photoswitch to regulate electron transfer pathway to the metal center.

Electrochemically converting CO₂ molecules into valuable chemicals and fuels opens up a promising route to utilize CO₂ source. To overcome the low efficiency and durability that hinder its practical applications, tremendous research efforts have been devoted to nano‐level or atomic‐level catalyst design. The advent of metal–organic frameworks (MOFs) provides novel opportunities for CO₂ reduction catalysts, which may integrate the respective advantages of traditional catalysts and single‐atom catalysts. In this review, we summarize the recent advances in two‐dimensional (2D) π‐conjugated MOF catalysts and discuss their practical applications in CO₂ reduction reaction (CO₂RR). First, we systematically introduce the development of electrocatalysts for CO₂RR applications. Meanwhile, various types of 2D porphyrin/phthalocyanine‐based MOFs and corresponding electrocatalytic performances arising from active‐site engineering, surface reconstruction, and thickness control are briefly overviewed. Finally, we highlight their major challenges and opportunities facing CO₂RR, and hope that this review can offer new insight into MOF catalyst design.