Facile synthesis of gold/palladium hydride heterostructures for efficient ethanol oxidation

Direct ethanol fuel cells (DEFCs) provide a portable and environmentally friendly power source with high energy density. However, the slow kinetic of the ethanol oxidation reaction (EOR) has hindered the commercialization of DEFCs. Palladium (Pd)-based nanomaterials are the best promising catalysts for EOR due to the high catalytic activities and relatively abundant reserves. In this paper, we developed a simple and green way for the preparation of palladium hydride (PdH0.43) and Au/PdH0.43 heterostructures. Ethylene glycol (EG) provided the source of H atoms for the formation of PdH0.43 in synthesis process. The as-synthesized PdH0.43 and Au/PdH0.43 nanocrystals were extremely stable under ambient conditions and annealing at 300 °C under Ar. Compared with PdH0.43 and commercial Pd/C, Au/PdH0.43 presented a higher mass activity of 2659 mA mg−1, a lower oxidation peak potential, and a higher catalytic stability for oxidizing ethanol. Remarkably, the improved catalytic performance might arise from the synergistically modulation of electronic structure, the enhanced resistance to poisoning products and the acceleration of electron transfer by the formation of palladium hydrides and abundant heterostructures of Au/PdH0.43. This work provides a promising reference for the development of metal-hydride nanomaterials and heterostructures as efficient catalysts.