Suppressing the Pd-C interaction through B-doping for highly efficient oxygen reduction

As a potential alternative to commercial Pt/C, carbon supported Pd nanoparticles (NPs) is powerful in facilitating ORR. However, a strong interaction usually existing between Pd and carbon probably hinders the expression of ORR activity. This work focuses on tuning the interaction between Pd and graphene for architecting high-performance ORR catalyst. The strong interaction between Pd and graphene was confirmed, rendering significant microstructural variation, e.g., the dramatic change of lattice disorder and vibration of surface C-H/C-O bond for the graphene support. Boron (B)-doping enables reversing such structural evolution and suppressing the Pd-C interaction. It literates the Pd from the interaction, increases its electrochemical specific surface area (ECSA) from 68 to 125 m(2) g(-1) and thereof contributes to the highly efficient ORR performance in alkaline solution with more feasible 4e(-) pathway on a 2.8 wt% Pd/C catalyst. Moreover, theoretical simulations further proved that B-doping enhances the electron transfer between Pd and the graphene support and probably benefits a 4e(-) pathway for ORR. (C) 2019 Published by Elsevier Ltd.