Antifouling Effect of ZnO on Ethanol Oxidation by Silver-Palladium Bimetallic Electrocatalyst

Fossil fuels will be finished and their prices are increasing. Therefore, there are many attempts to replace them with clean and renewable energies. Direct alcohol fuel cells are one of the interesting novel power sources has been extensively studied for stationary and portable miniature electric devices due to their high efficiency and low emissions of pollutants. However, there are some challenges to developing this type of fuel cells. Fouling of the catalyst layer in the alcohol fuel cells is a challenge, which reduces the catalyst performance and lifetime. In this study for the first time, the effect of zinc oxide (ZnO) as an antifouling agent for ethanol oxidation reaction (EOR) in alkaline media on the palladium-silver bimetallic catalyst is investigated. ZnO rods is electrochemically deposited at a short time and at a constant current on the carbon cloth (CC) substrate and then palladium and silver are electrodeposited simultaneously at room temperature and at a short time on the ZnO rods (AgPd/ZnO/CC). Cyclic voltammetry tests show the ethanol oxidation on the proposed anode is more complete and the CO-stripping experiments show ZnO can reduce the catalyst layer poisoning considerably. Also, the onset potential and ethanol oxidation peak position are significantly more negative than AgPd/CC, which means the EOR is easier on the proposed electrode.