Light-Promoted Hydrogenation of Carbon Dioxide-An Overview

Hydrogenation of carbon dioxide is considered as a viable strategy to generate fuels while closing the carbon cycle (heavily disrupted by the abuse in the exploitation of fossil resources) and reducing greenhouse gas emissions. The process can be performed by heat-powered catalytic processes, albeit conversion and selectivity tend to be reduced at increasing temperatures owing to thermodynamic constraints. Recent investigations, as summarised in this overview, have proven that light activation is a distinct possibility for the promotion of CO2 hydrogenation to fuels. This effect is particularly beneficial in methanation processes, which can be enhanced under simulated solar irradiation using materials based on metallic nanoparticles as catalysts. The use of nickel, ruthenium and rhodium has led to substantial efficiencies. Light-promoted processes entail performances on a par with (or even superior to) those of thermally-induced, industrially-relevant, commercial technologies.