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.