Photochemical Reduction of Low Concentrations of CO2 in a Porous Coordination Polymer with a Ruthenium(II)-CO Complex

摘要

Direct use of low pressures of CO2 as a C1 source without concentration from gas mixtures is of great interest from an energy-saving viewpoint. Porous heterogeneous catalysts containing both adsorption and catalytically active sites are promising candidates for such applications. Here, we report a porous coordination polymer (PCP)-based catalyst, PCP-RuII composite, bearing a RuII-CO complex active for CO2 reduction. The PCP-RuII composite showed improved CO2 adsorption behavior at ambient temperature. In the photochemical reduction of CO2 the PCP-RuII composite produced CO, HCOOH, and H-2. Catalytic activity was comparable with the corresponding homogeneous Ru-II catalyst and ranks among the highest of known PCP-based catalysts. Furthermore, catalytic activity was maintained even under a 5% CO2/Ar gas mixture, revealing a synergistic effect between the adsorption and catalytically active sites within the PCP-RuII composite.