Rh–Cu alloy nano-dendrites with enhanced electrocatalytic ethanol oxidation activity

The application of direct ethanol fuel cell(DEFC) has been bottlenecked by the sluggish ethanol oxidation reaction(EOR). Efficient electrocatalysts for the C-C bond cleavage are essential to promote EOR with high efficiency and C1 selectivity. Here, we prepared Rh–Cu alloy nano-dendrites(RhCu NDs) with abundant surface steps through controlled co-reduction, which exhibited significantly enhanced activity and C1 selectivity(0.47 m A cm((ECSA))-2, 472.4 mA mgRh-1, and 38.9%) than Rh NDs(0.32 mA cm((ECSA))-2, 322.1 mA mgRh-1, and 21.4%) and commercially available Rh/C(0.18 mA cm((ECSA))-2, 265.4 mA mgRh-1, and 14.9%).Theoretical calculations and CO-stripping experiments revealed that alloying with Cu could modulate the surface electronic structures of Rh to resist CO-poisoning while strengthening ethanol adsorption. In situ Fourier transform infrared spectroscopy(FTIR) indicated that the surface steps on RhCu NDs further promoted the C-C bond cleavage to increase the C1 selectivity. Therefore, optimizing the surface geometric and electronic structures of nanocrystals by rational composition and morphology control can provide a promising strategy for developing practical DEFC devices.