Addressing the CO₂ challenge through thermocatalytic hydrogenation to carbon monoxide, methanol and methane

Carbon dioxide's impact on global warming is a problem that should be addressed in the shortest term possible for the well-being of Earth's ecosystem and humanity. Among others, the diminution of atmospheric CO2 concentration by its conversion is an attractive alternative. Moreover, this valorisation method could lead to the formation of value-added compounds such as carbon monoxide, methanol or methane. Thermal hydrogenation is probably the most mature method to achieve this goal. However, this reaction should not be considered only as the reduction of CO2, but must be conceptualised as the conversion of carbon dioxide and hydrogen to value-added compounds and water. In that case, the source of hydrogen cannot be ignored. Due to the high stability of the carbon dioxide molecule, its reduction by thermal hydrogenation requires a catalyst. To be industrially relevant, the designed materials should present outstanding performance and stability with nearly full selectivity in the case of CO and CH4. This contribution compiles the newest material developments for each reaction, including discussions of their behaviour and comparison of performances.