3D Robust Carbon Aerogels Immobilized with Pd₃Pb Nanoparticles for Oxygen Reduction Catalysis

Development of desired electrocatalysts with high activity, excellent stability, and high selectivity for oxygen reduction reaction (ORR) is of significant importance for fuel cells. Herein, a high-efficiency electrocatalyst for the ORR is reported which utilizes a cross-linked carbon aerogel of reduced oxide graphene (rGO), and carbon nanotubes (CNTs) functioned as a three-dimensionally (3D) scaffold for anchoring ordered Pd3Pb nanoparticles (Pd3Pb/rGO-CNTs). The Pd3Pb/rGO-CNTs were synthesized by a facile and scalable route, mainly depending on the formation of a poly(vinyl alcohol) cross-linked GO-CNTs double-network hydrogel that allows for the efficient capture of highly active Pd3Pb particles after pyrolysis. The resulting composite exhibits remarkable ORR performances in terms of high half-wave potential, excellent stability, and methanol tolerance ability, resulting from the synergistic effect of ordered structure of Pd3Pb phase and 3D interconnected double-network of rGO-CNTs aerogels. The ordered Pd3Pb intermetallic compounds mainly work as the active centers for the ORR, while rGO-CNTs aerogels not only prevent Pd3Pb nanoparticles from aggregation but also provide open and accessible pores for fast transportation of reactants to the active centers.