Nonthermal Plasma-Assisted Enhanced CO₂ Conversion over NiOx/γ-Al₂O₃ Catalyst

The utilization of the dielectric barrier discharge (DBD) plasma process presents a promising avenue for transforming carbon dioxide (CO2) into valuable compounds. In this research, we explore the integration of DBD plasma with a NiOx/γ-Al2O3 catalyst to amplify the efficiency and selectivity of the conversion of CO2 into carbon monoxide (CO). A series of NiOx-loaded on γ-Al2O3 catalysts were synthesized through wet impregnation and employed in the DBD plasma reactor. The synergy between nonthermal plasma and NiOx/γ-Al2O3 resulted in a significant enhancement in CO2 conversion, particularly demonstrating a notable increase in the energy content of produced carbon monoxide (CO). Enhanced conversion rates and selectivities were observed. Notably, the NiOx/γ-Al2O3 catalyst with a 15 wt % loading exhibited the highest CO2 conversion of approximately ∼9% at an applied voltage of 22 kV, accompanied by an energy efficiency of 1.13 mmol kJ–1. This study provides a comprehensive analysis of the impact of plasma catalyst coupling on CO2 conversion into CO, showcasing the potential of hybrid DBD reactor systems for large-scale CO2 conversion and contributing to sustainable and value-added fuel production. The superior performance of the hybridized system is attributed to enhanced charge deposition and modified gas-phase chemistry resulting from the integration of the catalyst. Furthermore, we employed BOLSIG+ software to calculate the mean electron energy and electron energy distribution function for different packing conditions, enhancing our understanding of the system's behavior and contributing valuable insights to the overall study.