Nonequilibrium CO2 utilisation via vibrational activation in plasma catalysis.

With the rapid expansion of renewable electricity, CO2 conversion into fuels and chemicals is attracting growing interest as a route toward circular carbon utilisation. However, the high chemical stability of CO2 makes its efficient activation a central challenge. Molecular vibrational excitation can couple with reaction coordinates, thereby reducing the translational energy required to access transition-state regions and enhancing reactivity. Nonthermal plasma can generate vibrationally excited CO2 under nonequilibrium conditions, offering a practical route to exploit vibrational activation in catalytic reactions. This Feature Article reviews how vibrational energy promotes CO2 activation and examines the generation and relaxation of vibrationally excited CO2 in plasma, together with its relevance to catalytic surface reactions. Particular emphasis has been placed on our mechanistic studies of plasma-catalytic CO2 conversion, in which vibrationally excited CO2 is proposed to couple with surface reaction coordinates and facilitate elementary steps that are difficult to achieve thermally. These findings provide a basis for designing plasma-catalytic systems through molecular-level control of energy distribution and surface reactivity.