Enhanced CO2 conversion by frosted dielectric surface with ZrO2 coating in a dielectric barrier discharge reactor

The direct conversion of CO2 into CO and O2 by dielectric barrier discharge (DBD) non-thermal plasma is effective with simple setup, easy on/off operation and flexibility to the CO2 source. Herein, we demonstrated the frosted dielectric surface without and with ZrO2 coating can significantly improve the conversion and energy efficiency of the plasma CO2 decomposition in a DBD reactor, compared to the conventional un-frosted dielectric surface without ZrO2 coating. The use of the frosted dielectric surface increases the dielectric capacitance, mean electron energy and micro-discharge channels, leading to increased CO2 conversion and energy efficiency. The coating of ZrO2 of a high dielectric constant further improves the discharge performances with further increased CO2 conversion and energy efficiency. The highest energy efficiency of 7.7% was achieved within the tested conditions. The effect of CO2 adsorption on ZrO2 coating is negligible because of the low coating amount.