CO2 Hydrogenation to Formate with Immobilized Ru-Catalysts Based on Hybrid Organo-Silica Mesostructured Materials

The hydrogenation of CO2 to formic acid can be carried out by numerous homogenous catalysts, while efficient heterogeneous catalysts are rare. In this work, we successfully synthesize an immobilized lutidine-derived pincer-type N-heterocyclic carbene ruthenium complex based on a mesoporous organo-silica hybrid material using sol-gel direct synthesis in the presence of structure directing agents and click chemistry as the two key pillars of this strategy. This material efficiently catalyzes the hydrogenation of CO2 into formate with turnover numbers reaching 18000 within 24 hours, surpassing the performance of the corresponding homogeneous complexes.