Pd3Pb bimetallic aerogels for anti-poisoned oxygen reduction reaction

Abstract

Palladium (Pd) plays a vital role in oxygen reduction reaction (ORR) for direct methanol fuel cells due to its excellent activity, but it still suffers from CO poisoning and low CH3OH tolerance. Herein, for the first time, the Pd3Pb bimetallic aerogels (BMAs) were synthesized by ionic liquid assisted strategy for boosting ORR performance. The Pd3Pb BMAs possess excellent ORR activity and anti-poisoning property in 0.1 M KOH and maintain their original ORR activity after 10,000 cycles even in poisoning circumstances, outperforming Pd metallic aerogels and the commercial Pd/C. Mechanism studies show that the strong interaction between Pd and Pb, as well as the abundant unsaturated sites of the Pd3Pb BMAs are beneficial to optimizing the adsorption and dissociation of intermediates during ORR, while suppressing the adsorption of CO and CH3OH. This work demonstrates a novel route to the rational development of excellent active and anti-poisoned ORR electrocatalysts based upon BMAs.