Synthesis of boron doped graphene for oxygen reduction reaction in fuel cells

Boron atoms, with strong electron-withdrawing capability, are doped into graphene frameworks forming boron doped graphene (BG) via a catalyst-free thermal annealing approach in the presence of boron oxide. Atomic force microscopic (AFM) and transmission electron microscopic (TEM) characterizations reveal that the as-prepared BG has a flake-like structure with an average thickness of ca. 2 nm. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that boron atoms can be successfully doped into graphene structures with the atomic percentage of 3.2%. Due to its particular structure and unique electronic properties, the resultant BG exhibits excellent electrocatalytic activity towards oxygen reduction reaction (ORR) in alkaline electrolytes, similar to the performance of Pt catalysts. In addition, the non-metallic BG catalyst shows long-term stability and good CO tolerance superior to that of Pt-based catalysts. These results demonstrate that the BG, as a promising candidate in advanced electrode materials, may substitute Pt-based nanomaterials as a cathode catalyst for ORR in fuel cells as well as other electrochemical applications similar to the reported nitrogen doped graphene.