Pd-Ni Electrocatalysts for Efficient Ethanol Oxidation Reaction In Alkaline Electrolyte

Abstract: Lignocellulosic biomass-derived ethanol is among the most promising fuel candidates to supply future energy needs. The development of anion exchange membrane renders the possibility of ethanol oxidation by using non-platinum catalysts with high efficiency, which significantly reduces the cost of direct ethanol fuel cells and makes it attractive for large-scale fuel cell applications. It has been found that Pd has a competitive ethanol oxidation reaction (EOR) as Pt in high pH media. The theoretical calculation predicts that Pd-Ni could have high EOR activity due to the synergetic effect of Ni element. Here, we report a solution-phase reduction approach to prepare carbon supported Pd-Ni nanoparticles with different Pd-Ni compositions and characterize them by XRD, TEM, HR-TEM, TGA, ICP-AES. The characterizations reveal that these Pd-Ni catalysts have small diameters of around 3 nm and narrow size distributions. The catalytic activities towards EOR are carried out in 1.0 M NaOH + 1.0 M C₂H₅OH by cyclic voltammetry and chonoammeperometry, and to our knowledge, the highest EOR mass activity and stability on PdxNiy/C catalysts have been demonstrated. We also find the EOR activity is strongly correlated with Pd-Ni composition and structure, especially the Pd-Ni interaction/contact on catalyst surface. Our latest progress in this area will be presented as well.