Defect-Rich and Single-Crystalline PdCu Ultrathin Nanowires Promoting Ethanol Oxidation Electrocatalysis

Abstract

Developing high-performance electrocatalysts for the ethanol oxidation reaction (EOR) is greatly significant for the practical application of direct ethanol fuel cells, but it is still unsatisfactory. In this manuscript, we reported a facile aqueous synthesis of PdCu ultrathin nanowires (UNWs) as a highly active and stable electrocatalyst for EOR electrocatalysis. The synthesis relied on the columnar nucleation of PdCu alloys via co-reduction of Pd and Cu precursors in an aqueous solution with a highly hydrophobic dioctadecyldimethylammonium chloride as the structure-directing surfactant. PdCu UNWs featured ultrathin diameter (∼3.2 nm), defect-rich surface (high-index site), single-crystalline structure, and well-alloyed composition. They disclosed the remarkable mass activity of 3.02 A mgPd–1 and the good chronoamperometric and cycling stability for EOR electrocatalysis, both of which are better than its counterpart catalysts and commercial Pd/C. Mechanism studies further confirmed that PdCu UNWs had much better diffusion ability and lower activation energy based on their structural and compositional add-in synergies.