Bimetallic Nanostructures as Electrocatalysts for Ethylene Glycol Oxidation Process

Nowadays, the increasing worldwide energy demand and environment concerns lead to extensive research into power sources with low pollution and high energy conversion efficiency. Direct alcohol fuel cells (DAFCs) are considered as one of the studied fields in this regard due to their unique properties, including high energy density and relatively eco-friendly by-products. The commercialization of fuel cells depends on several factors, such as membrane, anodic and cathodic catalysts. However, the slow kinetic of alcohols oxidation on anodic catalysts due the need to break C-C bond for complete oxidation to CO2 is basic challenges in the development of DAFCs. To overcome this problem as well as increasing the activity, durability, and decreasing the cost of fuel cells, the development of new electrocatalysts is necessary. In this study, palladium-iridium (PdxIr) nanostructures were synthesized in different atomic ratio with solvothermal method in the presence of oleylamine as solvent, surfactant, and reducing agent. Carbon Vulcan XC-72R was used as a substrate in order to synthesize bimetallic nanocatalysts with the best distribution and particle size. This activated carbon has the highest electrical conductivity at low loading levels and has the advantage of higher dispersion in the selected medium compared to carbon compounds. The prepared electrocatalysts were characterized by XRD, TEM and FESEM-EDX. The performance of as-prepared nanocatalysts was evaluated for the reactions of ethylene glycol (EG) electro-oxidation in alkaline media by cyclic voltammetry, linear sweep voltammetry, and chronoamperometric measurements. The results demonstrate that the introduction of Ir in Pd structure can obviously promote the EG oxidation performance in the alkaline medium. Compared with single component catalysts (Pd and Ir), the as-prepared PdxIr/VC electrocatalysts exhibit higher activity and better stability for the electrooxidation of EG with good resistance to CO.