Carbon dioxide can be electrochemically converted into feedstocks for many industrial processes, such as the manufacturing of synthetic fuels and chemicals. This work focuses on the structure-functionality relationship between Au, Sn, and bimetallic AuSn catalysts and their CO2 reduction performance in an H-Cell at varying current densities. X-Ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), and atomic force microscopy (AFM) were used to determine the crystal structure, surface morphology, and composition of compositionally variant bimetallic thin films of Au-Sn before and after electrolysis. The electrochemical activity for each bimetallic film was measured in terms of electrode current and product selectivity as a function of applied current density and catalyst composition. The results of this work show that not all combinations of metals for CO2 reduction can improve catalyst activity toward a desired product and that a detailed material characterization can help in drawing structure-functionality relationships between a catalyst and its activity.