Carbon dioxide (CO2) decomposition was performed at a normal atmosphere and room temperature in dielectric barrier discharge microplasma reactors to reduce CO2 emissions and convert CO2 into valuable chemical materials. The outlet gases, including CO2, CO, and O-2, were analyzed with gas chromatography. The results indicated that the conversions of CO2 in dielectric material-packed reactors were all higher than that in nonpacked reactors. Particle size, dielectric constant, particle morphology, and acid-base properties of the dielectric materials (including quartz wool, quartz sand, -Al2O3, MgO, and CaO) all affected the CO2 decomposition process. The conversion of CO2 and energy efficiency achieved the highest values of 41.9 and 7.1% in a CaO-packed reactor for the higher dielectric constant and basicity of CaO. Quartz wool was also an excellent dielectric packing material because its fiber structure provided rigid sharp edges. (c) 2014 American Institute of Chemical Engineers AIChE J, 61: 898-903, 2015