采用低温固相反应法制备了直接甲醇燃料电池用PtSn/C阳极催化剂,采用XRD、TEM等测试方法对催化剂的晶体结构和粒径大小进行了表征.结果表明:采用低温固相反应法制备的PtSn/C催化剂和Pt/C催化剂均表现为Pt的fcc晶体结构;Sn的加入导致Pt的晶胞参数增大;与同法所制Pt/C催化剂相比较,PtSn/C催化剂中金属Pt在碳载体上分布较均匀,金属粒子的粒径较小,平均粒径约为4.8nm,从而具有更大的反应表面积.电化学测试表明,对于甲醇电氧化,PtSn/C催化剂具有比Pt/C催化剂更强的催化能力.
The PtSn/C catalyst was prepared by the low-temperature solid phase reaction method. X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM) were used to characterize the crystallinity and particle size of the catalyst. The results indicate that the PtSn/C and Pt/C catalyst prepared by the same low-temperature solid phase reaction method both have platinum fcc structure. The addition of Sn can increase the lattice parameter of Pt. Compared with the Pt/C catalyst prepared by the same method, the PtSn/C catalyst shows a higher dispersion and a smaller particle size and its mean particle size is about 4.8 nm, therefore the PtSn/C catalyst has a higher active specific surface area. The results of electrochemical measurements demonstrate that the PtSn/C catalyst has a better electrocatalytic activity for the methanol oxidation than Pt/C catalyst.