PtPd alloy embedded in nitrogen-rich graphene nanopores: High-performance bifunctional electrocatalysts for hydrogen evolution and oxygen reduction

Searching for high-efficiency and low-cost bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) has been actively encouraged for their promising applications. We report a facile strategy to prepare PtPd alloy embedded in nitrogen-rich graphene nanopores (Pt2Pd/NPG) as highly efficient bifunctional electrocatalysts for HER and ORR. The as-prepared Pt2Pd/NPG exhibits prominent onset potential, excellent stability, good kinetic current density, and remarkable corrosion resistance to HER and ORR. Density functional theory (DFT) calculations reveal that the remarkably enhanced performance of Pt2Pd/NPG originated from the robust conjugation between the Pt2Pd alloy nanoparticles and nitrogen-rich graphene nanopores, thereby leading to the synergistic effect of both interfaces. The nanopores also modulate the electronic properties of Pt2Pd alloy nanoparticles, which improve the durability during HER and ORR. A novel approach for preparing high-performance bifunctional electrocatalysts with embedded metal alloy in nitrogen-rich carbon is presented. The process has potential applications in energy conversion and storage. (C) 2016 Elsevier Ltd. All rights reserved.