Switching of the CO2 hydrogenation selectivity via organic amines over ionic porous polymer-supported Ru single atom catalyst

Converting carbon dioxide into high-value chemicals through catalytic means is one of the most promising approaches for CO 2 utilization. In this work, the ionic porous polymer-supported Ru single-atom catalysts were constructed for CO 2 hydrogenation reactions. It is noteworthy that the anions of the polymers exerted a significant influence on porosity and CO 2 adsorption capacity, which are crucial for achieving efficient CO 2 hydrogenation under mild conditions. Especially, the products of CO 2 hydrogenation on the polymer catalyst can be switched by tuning the type of amines, i.e. , with the assistance of tertiary amine, CO 2 /H 2 and methanol can produce methyl formate efficiently. However, CO 2 /H 2 , the primary and secondary amines switched to afford the corresponding formamides by N-formylation reaction with the identical catalyst. The detailed characterization demonstrates that Ru is only partially coordinated with phosphine ligand tethered in the polymer framework, while the remaining uncoordinated free phosphine bearing lone-pair electrons can activate CO 2 through a synergistic interaction with the moiety of ionic liquids, thereby enhancing the catalytic activity. The catalytic system exhibits high efficiency, stability and ease of recyclability, allowing for reuse up to ten times.