Converting CO2 to CO via a Plasma-Catalyst Coupled Pathway with Ultrahigh Single-Pass CO2 Conversion and ∼100% CO Selectivity

The plasma-catalytic conversion of CO2 to CO through reverse water gas shift (RWGS) reactions offers an appealing route for storing intermittent renewable electricity and incorporating the “3Rs” (i.e., reduce, reuse and recycle) concept for CO2 mitigation and utilization, but the lack of efficient catalysts matched to the plasma environment has hindered the widespread deployment of this technology. Here, we report that OV–In2O3 catalysts with abundant oxygen vacancies (OV) can perfectly couple to the RWGS reaction under plasma conditions via a H radical-dominated gas-phase mechanism. In this mechanism, gas-phase H radicals generated by synergistic promotion of oxygen vacancies and plasma achieved highly efficient CO2 activation in the gas phase (plasma), which preventing CO2 activation from the energy-intensive CO2 adsorption-dissociation mechanism, thus significantly improves the efficiency of CO production. With this strategy, plasma–OV-In2O3 shows an ultrahigh single-pass CO2 conversion of 60.8% with ∼100% CO selectivity under ambient conditions. This study delves deeply into the plasma-catalytic CO2 activation process and proposes a H radical-dominated gas-phase mechanism for CO2-to-CO conversion, offering a pathway for seamlessly integrating CO2 mitigation with energy storage and value-added chemical product synthesis.