Non-thermal plasma CO2 conversion enhanced by CeO2-doped BaTiO3 and internal electrode cooling

Abstract

This work investigates the combined impact of using cerium oxide (CeO2) as a catalyst and internal electrode cooling on CO2 conversion into CO in a non-thermal plasma reactor packed with barium titanate (BaTiO3). BaTiO3 is successfully modified with CeO2 via a wetness impregnation method, yielding samples with 0%, 3%, 17%, and 57% CeO2 loadings. It is observed that a low CeO2 loading of 3% increased the CO2 conversion and energy efficiency by up to 38% compared to the undoped BaTiO3, while higher loadings (17% and 57%) led to reduced performance. The use of a cooling strategy through the inner electrode, using air convection (passive cooling) or water flow (active cooling), increases both CO2 conversion and energy efficiency by strengthening plasma generation and reducing the recombination of CO and O2. Specifically, conversion increases from 18% without cooling to 36% with passive cooling, and further to 47% when combined with 3% CeO2 doping and active water cooling. In parallel, the energy efficiency increases from 0.3 - 2% (undoped, uncooled) to 0.5 - 16% with 3% CeO2 doping under both passive and active internal cooling.