A synthesis of CO-tolerant Nb_2O_5-promoted Pt/C catalyst for direct methanol fuel cell; its physical and electrochemical characterization

摘要

A Pt-Nb_2O_5/C electrocatalyst was synthesized by a two-step process as an anode material in direct methanol fuel cell (DMFC). The Pt-Nb_2O_5/C catalysts heat-treated at different temperatures (400 and 500 ℃) in flowing N_2 were characterized by various methods such as inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, transmission electron microscopy, and X-ray photoemission spectroscopy (XPS). The heat-treated Pt-Nb_2O_5/C catalyst at 400 ℃ showed the best electrochemical activity for CO and methanol oxidations among the prepared catalysts. The XPS results showed the electronic structure change of Pt, indicating a formation of interaction between Pt and Nb_2O_5. It is suggested that a synergistic effect between Pt and Nb_2O_5 enhances the electrocatalytic activity for CO and methanol oxidations. We believe that Nb_2O_5-promoted Pt/C catalyst may be regarded as one of the attractive candidates as an anode material in DMFC.