B-N Codoped Graphene as a Novel Support for Pd Catalyst with Enhanced Catalysis for Ethanol Electrooxidation in Alkaline Medium

Abstract

B-N-doped graphene (B-N-G) was designed as a novel carrier for Pd nanoparticles (NPs) and it was used as the electrocatalyst for ethanol oxidation in alkaline medium. B and N species were introduced onto the graphene surface by the process of B and N sequentially incorporation. According to XPS results, most of B and N atoms are bonded with C atoms separately, which could increase the spin density and activate the neighboring carbon atoms, and further cause strong interaction between Pd and substrates. So, Pd/B-N-G catalyst presents most metallic Pd content and least Pd2+ content, as well as decreased Pd-3d binding energy. TEM results showed that Pd NPs dispersed most uniformly with an average size of 2.9 nm on Pd/B-N-G. Electrochemical evaluation showed that Pd/B-N-G catalyst exhibited much improved catalytic performance and poisoning tolerance for ethanol oxidation in alkaline medium as compared to those of Pd/B-G, Pd/N-G and Pd/G. B-N-G carrier promoted the high dispersion of Pd NPs due to the coexisting active sites introduced by B-N codoping, which improved the utilization efficiency of Pd. Furthermore, the enhanced electronic effects between Pd particles and the support caused by B-N codoping, may cause synergistic effects and thereby eventually improve the catalytic performance.