Mechanistic Insights of Photocatalytic CO2 Reduction: Experimental versus Computational Studies

To stop the global warming, a complementary alternative to the decrease of CO2 production is the reduction of its amount in the atmosphere by capture and transformation into consumer products. One of the most interesting primary products is CO, used to synthesise liquid fuels. Perhaps the most attractive way of reducing CO2 to CO is the photocatalytic route. To know the details of the mechanism of this reaction can help in the design of more efficient catalytic systems. In this review, we compile the studies, undertaken from both computational and experimental approaches, of the reaction mechanism of the photoreduction of CO2 to CO by molecular catalytic systems based on transition metal complexes. The combination of experimental and computational studies can be crucial to achieve the goal aimed. Computational and experimental approaches can complement each other in the study of chemical reactivity. This review compiles the works where both approaches were used to elucidate the mechanism of the photochemical reduction of CO2 to CO catalysed by transition metal complexes. The numerous steps of the reaction enable a large variety of possible reaction paths.