分散铂修饰聚苯胺电极的制备及其催化性能

利用扫描电子显微镜(SEM)、循环伏安(CV)方法,探讨了在合成分散铂修饰聚苯胺复合电极(Pt-PANi/pt)时能够影响聚苯胺表面形貌的质子酸种类以及铂微粒的电沉积方法。实验发现,采用循环伏安法制备聚苯胺时,在硝酸介质中制备的纳米聚苯胺纤维细小、膜层稳定、能够提高复合电极的催化活性,比在硫酸介质中制备的聚苯胺更适合作为Pt催化剂的载体;沉积分散铂所采用的电化学方法不同导致铂的生长方式不同,造成复合电极催化活性的差异。采用脉冲电位法,通过缩短脉冲沉积时间,能够使铂微粒数目增多、分布均匀,有效提高铂的比表面积,制备的Pt-PANi/pt复合电极显示出了较好的催化活性。

Synthesis of Platin/Carbon XC72R Nanocomposite Using as Electrocatalyst for Direct Methanol Fuel Cells

Platinum/Carbon XC72R （Pt/C） nanocomposite was synthesized in-situ by polyol method. Precursor of hexahydrated chloroplatinic acid H2PtCI6-6H2O was reduced by EG （ethylene glycol） so as to form Pt nanoparticles which were deposited on the surface of carbon. Pt/C composites （treated or untreated carbon） were synthesized at pH - 6.5 and pH = 11. The XRD pattern of Pt/C showed peaks assigned to the crystalline structure of Pt and carbon. TEM images showed that Pt nanoparticles on carbon were ultrafine spheres and the particles obtained sizes from 2 to 6 nm which are mostly concentrated on size of 3 nm. The electrocatalytic activity of Pt/C catalysts toward methanol oxidation was examined by CV （cyclic voltammetry）. Pt/treated XC72R （pH = 11） at potential （0.69 V） exhibited better electroactivity （628 mA/mg Pt）.