以切短多壁碳纳米管为载体制备高活性Pt/SCNT及PtRu/SCNT燃料电池催化剂

Shortened Carbon Nanotubes as Supports to Prepare High-Performance Pt/SCNT and PtRu/SCNT Catalysts for Fuel Cells

采用乙醇为助磨剂,利用球磨的方法将5-15μm长的多壁碳纳米管切短成长度约为200nm,并且分布较为均匀的短碳纳米管(SCNT).以SCNT为载体,采用有机溶胶法制得了含铂20%(w)的Pt/SCNT及PtRu/SCNT催化剂.实验发现:对于甲醇的阳极电氧化过程,以切短碳纳米管为载体的Pt/SCNT催化剂具有比相同条件制得的Pt/CNT催化剂高得多的催化活性,前者甲醇氧化峰电流密度是后者的1.4倍,并且远远高于商品的Pt/C催化剂.同时我们发现添加了钌的PtRu/SCNT具有比不含钌的催化剂更好的活性.采用X射线衍射(XRD)、透射电镜(TEM)、比表面积分析(BET)等方法对催化剂进行表征,结果表明,切短碳纳米管的晶相结构并未改变,但Pt/SCNT和PtRu/SCNT催化剂的比表面积和电化学活性得到了显著的提高.

Ball milling was used with ethanol as a milling aid agent to shorten the carbon nanotubes （SCNT） from 5-15 μm to ca 200 nm.We prepared a platinum catalyst Pt/SCNT and a platinum ruthenium alloy catalyst PtRu/SCNT using the shortened nanotubes as supports by a colloidal method.We found that Pt/SCNT showed much higher activity than Pt/CNT during the anodic oxidation of methanol.The peak current density for Pt/SCNT was 1.4 times as high as that of Pt/CNT and it was also much higher than that of the commercial Pt/C catalyst.Furthermore,we found that PtRu/SCNT showed higher activity than that of Pt/SCNT and PtRu/C catalysts.The results of X-ray diffraction analysis （XRD）,transmission electron microscopy （TEM）,and the specific surface area （BET） method.revealed that the crystal structure of the nanotubes did not change before or after shortening whereas the special surface area and the electrochemical activity increased significantly.