Reductive gas-phase ion chemistry of simple oxocarbons in the presence of alkali and alkaline earth metals

Abstract

In a circular carbon economy, carbon dioxide (CO2) is recycled and used as a molecular building block to make fuels, chemicals and materials, driven by renewable energy sources. Hence, the molecule represents a potential replacement for oil, natural gas and coal as one of the primary sources of carbon. A major bottleneck stems from the fact that CO2 requires activation before it can be converted. This work explores the activation and reduction of CO2 by the alkali metal and alkaline earth metal chloride anions on a fundamental level. It sheds light on relevant factors in the conversion of CO2 to valuable products such as oxalate (C2O42−) and carbon monoxide (CO), as well as further conversion of the latter. The aforementioned processes proceed via metal-CO2 intermediates—chemical species formed during conversion of reactants to products—and this thesis links their properties to the extent of CO2 activation. Specifically, more complete electron transfer from the metal to CO2 and larger structural changes in the intermediates are associated with lower energetic demands for further reaction and conversion. These results could prove useful for the development of efficient CO2-recycling processes.