Efficient promotion of ethanol complete electrooxidation by anti-poisoning rhodium-bismuth alloy nanodendrites

Alkaline direct ethanol fuel cells are promising future energy technologies with a high energy-density, while the lack of robust anodic electrocatalysts limits their energy conversion efficiency due to serious poisoning and weak selectivity to the C1 pathway of ethanol oxidation reaction (EOR). Herein, rhodium-bismuth alloy nanodendrites (RhBi-NDs) are applied as an efficient and anti-poisoning electrocatalyst for EOR, which exhibit superior elec-trocatalytic performance, including a mass activity of 1068.9 mA mgRh  1 at 0.71 V, a 31.1% Faradaic efficiency for the C1 product, and an excellent stability of 40 h. The mechanism study indicates that Bi improves the oxidation ability of Rh to toxic intermediates by providing oxygen-containing species. The theoretical calculations disclose the electronic interaction between Bi and Rh, which tunes the adsorption energy of intermediates such as CH3CH2OH*, and CH3CO*, resulting in the suppression of C2 pathway and the promotion of C1 pathway for EOR on RhBi-NDs.

Automated summary

Alkaline direct ethanol fuel cells are future energy technologies with high energy density. However, the lack of robust anodic electrocatalysts limits their energy conversion efficiency. In this study, rhodium-bismuth alloy nanodendrites (RhBi-NDs) are used as efficient and anti-poisoning electrocatalysts for ethanol oxidation reaction (EOR), showing superior electrocatalytic performance with high mass activity, Faradaic efficiency, and stability. The mechanism involves the improvement of oxidation ability and electronic interaction between Bi and Rh, which suppress the undesirable C2 pathway and promote the desired C1 pathway for EOR on RhBi-NDs.