It is difficult to separate catalytic effects from those derived from mass transport or interactions with the plasma in the reactor. Atomic layer deposition (ALD) is a self-limiting, highly controlled growth process that is capable of depositing thin films with atomic control over layer thickness and composition. ALD has also been shown to be capable of conformally coating the nanopores of support materials without changing the overall porosity or microstructure of the support. This control, along with the low pressure deposition environment, allows for the coating of high aspect ratio or geometrically complex features, such as microwires or foams, without the line of sight restrictions imposed by other coating techniques such as sputtering or flame-spray. ALD has been used to synthesize electrocatalysts or thermal catalysts on supports for CO2 reduction. With respect to plasma catalysis, ALD has primarily been used as a method for applying catalysts developed for pollutant degradation and non-oxidative methane coupling. In this work, we characterize the activity of ALD-synthesized thin films of metal oxide catalysts on an aluminosilicate support for catalyzing CO2 reduction in a DBD plasma reactor. This approach regularizes the structure of the support and isolates the catalytic effects of the nanoscale, conformal coating. We used ALD to prepare three metal oxide catalysts of interest for CO2 reduction in a DBD plasma reactor to produce CO and O2. TiO2 has been investigated as a plasma CO2 reduction catalyst, and is therefore a well-known catalyst around which to develop this technique. Al2O3 was chosen because as it has been shown to be much less active for plasma CO2 reduction than other metal oxides and has often been used as a support material for other catalysts. ZnO is typically used in DBD plasma reactions as a support material for other co-catalysts such as Pd or Cu for CO2 hydrogenation reactions. While both TiO2 and Al2O3 behaved as expected, we observed a significant increase in the activity of ZnO with increasing reactor power. Regularizing the catalyst structure shows that this transition is only explained by a transition in the behavior between the ZnO surface and the plasma. There is significant catalytic behavior from a material that is conventionally considered a support material. More generally, this work shows that ALD can be used to isolate catalytic activity from other effects (mass transport, plasma variability near dielectric interfaces) in complex plasma reduction reactions.