Enhancing CO₂ Conversion via Atmospheric Pressure Glow Discharge Plasma Jet Coupled with Catalysts

As one of the most consensus goals around the world, reduction of carbon emissions has attracted huge attention from academic and industry communities for developing renewable energy sources and carbon capture techniques. Nonthermal equilibrium plasma catalysis has been proven to be a very promising way for CO2 conversion into high-value-added products; however, the synergistic catalytic mechanism between the plasma and various catalysts remains a challenge. In this work, we designed a reactor of atmospheric pressure glow discharge (APGD) plasma jet coupled with V2O5/TiO2 nanocomposite catalysts and studied the influence of V2O5 mass fraction, catalyst pretreatment, and reaction plasma parameters on the CO2 dissociation performance. Results showed that the designed reactor could introduce high-density plasma to the downstream area and maintain lower gas temperature, allowing the collaboration between APGD and the V2O5/TiO2 catalyst. The XRD analysis indicated that the solid solution phase TiVO4 could be formed in catalysts by V2O5 doping and reach a maximal content at a mass fraction of 30%, which determined the most excellent redox ability of the catalyst. The pretreatment of the as-prepared catalyst by Ar dielectric barrier discharge (DBD) plasma increased the oxygen vacancy density of the catalyst, thereby raising the conversion rate by 18.43%. Moreover, the transition regime between laminar and turbulent states was found to be the optimal configuration for CO2 dissociation. The reaction pathway was proposed for CO2 dissociation synergistically catalyzed by an APGD plasma jet and V2O5/TiO2. Ultimately, the maximum conversion of 14.88% and energy efficiency of 40.45% were simultaneously achieved, which were superior to the results of most atmospheric pressure plasmas. This work opens an avenue to develop plasma technology for sustainable CO2 utilization.