(569as) Systematic Theoretical Screening of Metal-Ions@Ti-MOF for Catalytic Solar-Driven CO2reduction

Solar-driven CO₂ reduction reaction (CO₂RR) into valuable products such as methanol represents one of the most effective strategies for transforming the greenhouse gas into valuable fuel. This calls for the selection of highly active materials to catalyse the process, as for instance, single-atom metal catalysts. Interestingly, metal-organic frameworks (MOFs) possess a tuneable crystalline porous structure that enhances the surface area exposed for reaction and mitigates the electron-hole recombination pathways, meanwhile offering the opportunity to modify their electronic properties via the incorporation of metal ions. In particular, the Ti-based MOF MIP-177 can be envisaged as a potential candidate for CO₂RR owing to remarkable photoconductivity combined with a high structural and chemical stability and its low-toxicity that already made this MOF as an effective catalysis for the dehydrogenation of formic acids. In this work, we assessed the photocatalytic behavior of MIP-177 incorporating nine different metal ions (Figure 1a) that act as single-metal catalysts by means of Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations. To this end, we analyzed the thermodynamics of the distinct reaction pathways followed by the CO₂ conversion into methanol and evaluated the impact of metal ion incorporation on the excited state properties of the MOF. Notably, our results revealed Cu⁺ metal ion as the most effective single metal ion photocatalyst owing to its lower energy barriers for reaction, lower charge injection barriers to transfer electrons towards the MOF framework, enhanced solar light harvesting, and effective generation of charges for catalysis upon VIS light irradiation