Modulation of <i>p</i>-Block Electron Orbits in Metal–Organic Frameworks for CO₂ Capture and Electrochemical Reduction

Developing catalysts with excellent CO₂ capture capability and electrochemical CO₂ reduction reaction (CO₂RR) at a wide potential range simultaneously is significant but remains a formidable challenge. Here, two novel InMg defective trinuclear cluster-based MOFs (SNNU-41 and SNNU-42) with abundant <i>p</i>-block unsaturated coordinated sites were reported and exhibited good CO₂ capture and CO₂RR performance simultaneously. Due to the suitable micropores, SNNU-41 showed higher CO₂ capture ability at different adsorption pressure conditions. On account of the rigid framework and the closer <i>p</i> band center to Fermi level, SNNU-42 accelerated the conversion of CO₂ molecule to C1 efficiency. Notably, via adjusting the ratio of <i>p</i>-block metal (In) in the SNNU-42 framework, the performance of the CO₂RR was promoted drastically. SNNU-42 with the InMg (1:1.8) mixed cluster delivered an excellent Faradaic efficiency of 91.3% for C1 products and high selectivity of 72.0% for HCOOH at -2.5 V (vs Ag/Ag⁺) with a total current density of 77.2 mA cm^-2. This work provides a possibility for efficient CO₂ capture and CO₂RR electrocatalysts through the modulation of electronic structures and composition in MOFs.