Hollow PdCu nanocubes supported by N-doped graphene: A surface science and electrochemical study

• A series of N doped graphenes with different N atom species were synthesized by heat treatment process.
• Hollow PdCu alloy nanocubes with uniform size have been successfully assembled on the surface of N doped graphenes.
• H–PdCu/melamine-NG exhibits good electrocatalytic activity and stability for ethanol electrooxidation.

N doped graphenes (NGs) are believed to be promising materials for constructing novel hybrid composites with desirable functionalities and applications in many fields. Therefore, a better understanding of the NGs holds the key to a better performance of the hybrid properties. A facile and low-cost preparation of NGs supported hollow PdCu alloy nanocubes (H–PdCu) catalysts were introduced in this paper. To increase the stability and efficiency of the catalysts, a two-step strategy was employed, which included the preparation of NGs and the synthesis of hollow PdCu alloy nanocube catalysts. A series of NGs using melamine, polypyrrole (ppy) and polyaniline (PANI) as nitrogen source, respectively. The influence of the different N species (pyridinic N, pyrrolic N and graphite N) on the morphologies and corresponding electrical properties of H–PdCu nanoparticles were studied. The results indicate that NGs are successfully synthesized, and hollow PdCu alloy nanocubes are well-dispersed on the surface of them with a relatively narrow particle size distribution. Electrochemical characterizations reveal that the H–PdCu/melamine-NG catalyst has excellent catalytic activity and stability toward alcohols oxidation in alkaline electrolyte, which can serve as promising anode catalysts in direct alcohols fuel cells (DAFCs).