Abstract

This work presents homogeneous Ru complexes containing sulfur-based ionophilic ligands that exhibit high dual catalytic activity for CO2 hydrogenation and formic acid dehydrogenation under mild conditions. Indeed, the ionophilic [RuCl2(SNS)(PPh3)] complexes promote the reduction of CO2 to formate using DBU as a base, either in organic solvents (CH3CN or CH3CN/THF mixture, achieving TOFs of up to 1500 h-1) or in ionic liquids ([BMIm][NTf2], [OMIm][NTf2]) at 80 degrees C and 40 bar (20 bar CO2, 20 bar H2). Additionally, independent reactions demonstrated that formic acid can be dehydrogenated with TONs of up to 1540 at the same temperature. Notably, one-pot recycling experiments revealed that the ionophilic Ru complexes are also capable of promoting CO2 hydrogenation to formate and its subsequent dehydrogenation at 80 degrees C, providing evidence that these ionophilic Ru complexes are active sulfur-based catalysts for enabling a versatile cycle of hydrogenation/dehydrogenation reactions.