关键词: Pt/SiC;低铂;氧还原反应;催化性能

Abstract: Pt/SiC cathode catalyst with 14; of platinum content was prepared by ethylene glycol refluxing method.The crystal structure , surface morphology and surface electronic structure were characterizated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).The electrocatalytic activities of Pt/SiC were characterizated by cyclic voltammetry(CV) and rotating disk electrode (RDE) techniques for oxygen reduction reaction (ORR).The results show that the average particle size of Pt in Pt/SiC catalyst synthesized at 180℃ is 3.4 nm and Pt is fcc structure.On the surface of SiC, Pt(0) is the main existence state, which is conducive to the adsorption and dissociation of O2 on the surface.The Pt/SiC-180 catalyst occupied a similar catalytic performance of commercial catalyst Pt/C(20;) for ORR.The onset potential for ORR at Pt/SiC-180 catalyst significantly shifts positively to 0.95 V, which is close to the onset potential for Pt/C electrodes (0.96 V).The ORR process at Pt/SiC-180 electrode is dominated by a 4-electron process with water as the product at low potential.Pt/SiC-180 catalyst has a higher stability toward ORR and better methanol tolerance than the commercial Pt/C in alkaline medium.Excellent catalytic activity and less platinum are expected to become the potential cathode catalytic material in fuel cell with low platinum .

Key words: Pt/SiC cathode catalyst with 14; of platinum content was prepared by ethylene glycol refluxing method.The crystal structure , surface morphology and surface electronic structure were characterizated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS).The electrocatalytic activities of Pt/SiC were characterizated by cyclic voltammetry(CV) and rotating disk electrode (RDE) techniques for oxygen reduction reaction (ORR).The results show that the average particle size of Pt in Pt/SiC catalyst synthesized at 180℃ is 3.4 nm and Pt is fcc structure.On the surface of SiC, Pt(0) is the main existence state, which is conducive to the adsorption and dissociation of O2 on the surface.The Pt/SiC-180 catalyst occupied a similar catalytic performance of commercial catalyst Pt/C(20;) for ORR.The onset potential for ORR at Pt/SiC-180 catalyst significantly shifts positively to 0.95 V, which is close to the onset potential for Pt/C electrodes (0.96 V).The ORR process at Pt/SiC-180 electrode is dominated by a 4-electron process with water as the product at low potential.Pt/SiC-180 catalyst has a higher stability toward ORR and better methanol tolerance than the commercial Pt/C in alkaline medium.Excellent catalytic activity and less platinum are expected to become the potential cathode catalytic material in fuel cell with low platinum .