Methanol-tolerant SePt/C: effects of Se content on the structure and electrocatalytic performance for oxygen reduction reaction

In order to develop high-performance methanol-tolerant cathode catalyst in direct methanol fuel cell (DMFC), Se-decorated Pt catalysts on carbon support (Se<^>Pt/C) are prepared using a two-step reducing method, which consists organic sol method for Pt nanoparticles on carbon carrier followed by the decoration of Pt/C with Se. Effects of Pt/Se atomic ratio on the physical properties and electrocatalytic performances for oxygen reduction reaction (ORR) are investigated. The results show that the surfaces of Pt nanoparticles are decorated with amorphous Se and PtxSey. The ORR activity on Se<^>Pt/C (Pt/Se atomic ratio = 1:0.20) is close to that on Pt/C. When the molar ratio of Pt to Se decreases from 1:0.20 to 1:0.78, both the onset and half-wave potentials of ORR are negatively shifted. All the Se<^>Pt/C catalysts show better methanol-tolerant ability than Pt/C. The mechanism for ORR on Se<^>Pt/C is the same as that on Pt/C.