The abatement of volatile organic compounds (VOCs) from industrial exhaust gases is critical for
environmental compliance. Surface dielectric barrier discharge (SDBD) reactors enable plasma-
driven oxidation of hydrocarbons such as n-butane under ambient conditions. In this work, dual-
component MnO2/CaO catalyst coatings (2:1 and 3:1) are developed and evaluated against an
uncoated electrode configuration. The MnO2/CaO coatings achieve up to 87.5% n-butane conversion
and 95.0% CO2 selectivity at 2.5 slm total gas flow and 115 W power input without external heating,
clearly outperforming previous dual component systems. CaO functions as a low-permittivity scaffold
that enables increased MnO2 loading while stabilizing discharge behavior. It is proposed that the
dielectric properties and low work function of CaO promote pore-level microdischarges and enhance
secondary electron emission. These effects likely induce localized heating at active sites, selectively
activating MnO2 under discharge conditions. Overall, the results demonstrate a strong interplay
between plasma characteristics and catalyst architecture, providing a pathway toward more energy-
efficient VOC abatement.