Initially developed for more than 20 years ago, the copper over zinc and aluminum oxide (ZnO/Al2O3) catalyst system is used for low-pressure methanol synthesis. Recently, the Cu/ZnO/Al2O3 (CZA) was shown to be active in a dielectric-barrier discharge (low-temperature plasma). In this paper, the investigation on the copper as the active site of the catalyst was discussed on the basis of experimental results and its characterization analysis. The catalyst was attempted to aid the reaction performance of partial oxidation of methane in order to produce methanol. All CZA-based catalysts were successful in increasing methanol selectivity, and the Cu oxide performed better than a metallic-copper catalyst.