Copper catalyst was electrodeposited from a 0.01 M CuSO4 at EWE = 0 V vs SHE' for 10s followed by EWE = 0.15 V vs. SHE' for 1 min. Once the copper catalyst was plated onto the electrode, the electric current of the WE was held constant at 0 nA using the potentiostat to prevent any additional electrochemical changes to the catalyst. Morphological analysis of the catalyst in the original condition was performed at this point. Subsequently, the electrolyte was exchanged to KHCO3 or K2SO4 for the CO2 ER copper degradation analysis.