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

• Doping of the BaTiO 3 fixed bed with CeO 2 catalyst. • Cooling of the plasma reactor through the inner electrode. • The combined enhancement of conversion and energy efficiency through CeO 2 catalyst doping and temperature control. • The beneficial operation parameters for either passive air convection or active water cooling. This work investigates the combined impact of using cerium oxide (CeO 2 ) as a catalyst and internal electrode cooling on CO 2 conversion into CO in a non-thermal plasma reactor packed with barium titanate (BaTiO 3 ). BaTiO 3 is successfully modified with CeO 2 via a wetness impregnation method, yielding samples with 0%, 3%, 17%, and 57% CeO 2 loadings. It is observed that a low CeO 2 loading of 3% increased the CO 2 conversion and energy efficiency by up to 38% compared to the undoped BaTiO 3 , 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 CO 2 conversion and energy efficiency by strengthening plasma generation and reducing the recombination of CO and O 2 . Specifically, conversion increases from 18% without cooling to 36% with passive cooling, and further to 47% when combined with 3% CeO 2 doping and active water cooling. In parallel, the energy efficiency increases from 0.3 - 2% (undoped, uncooled) to 0.5 - 16% with 3% CeO 2 doping under both passive and active internal cooling.