The current research is focused on the decomposition of carbon dioxide (CO2) into carbon monoxide (CO) and oxygen (O2) in a non-thermal plasma reactor using dielectric barrier discharge (DBD) at ambient conditions. Pure CO2 was injected into the DBD reactor at a flow rate of 30 mL min-1, and the voltage was varied between 16 kV to 22 kV. The filamentary micro discharges generated during plasma has a significant effect on CO2 conversion. The effect of packing materials on CO2 conversion was investigated by packing non-catalytic materials such as quartz wool, glass capillary, glass wool, and glass beads in the discharge zone of the DBD reactor. Among the studied packing materials, quartz wool exhibited a maximum CO2 conversion of 9.3 % at a discharge power of 2.0 W and specific energy input (SEI) of 4.0 J mL-1. However, glass capillary exhibited the highest energy efficiency of 1.2 mmol kJ-1 at an SEI of 3.5 J mL-1. © 2022 Elsevier Ltd