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

Abstract

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.