The enhancement of CO 2 reduction in atmospheric-pressure, non-thermal plasma has been shown using a variety of catalyst systems with ranging composition, particle sizes, and morphologies. Improvements in CO 2 conversion can be attained by choice of catalyst material. However, inhomogeneity in the material distribution arising from the synthesis affects the catalytically active surface area and dielectric environment that modulates the plasma properties near the catalyst. Atomic layer deposition (ALD) can be used to control the composition of ultra-thin layers on support materials. We used ALD to synthesize metal oxide catalyst coatings on high surface area supports. We found that TiO 2 achieved significantly higher yields of CO 2 conversion (to CO and O 2 ) at low reactor power compared to ZnO or Al 2 O 3 , materials commonly used as a support for other catalysts. We also observed an unexpected increase in the catalytic activity on ZnO with increasing power. The results here suggest that ALD can unambiguously isolate the catalytic effects of materials in plasma reactors. Catalysts prepared by atomic layer deposition allow for comparisons between structurally-identical metal oxide catalysts for CO 2 reduction in non-thermal plasmas.