A Mixed-Metal Porphyrinic Framework Promoting Gas-Phase CO₂ Photoreduction without Organic Sacrificial Agents

A photoactive porphyrinic metal-organic framework (MOF) has been prepared by exchanging Ti into a Zr-based MOF precursor. The resultant mixed-metal Ti/Zr porphyrinic MOF demonstrates much-improved efficiency for gas-phase CO₂ photoreduction into CH₄ and CO under visible-light irradiation using water vapor compared to the parent Zr-MOF. Insightful studies have been conducted to probe the photocatalysis processes. This work provides the first example of gas-phase CO₂ photoreduction into methane without organic sacrificial agents on a MOF platform, thereby paving an avenue for developing MOF-based photocatalysts for application in CO₂ photoreduction and other types of photoreactions.