PtCr/C-Nafion 膜氧电极的电催化活性

氧还原电催化剂的研究对聚合物电解质膜燃料电池技术的发展具有极其重要的意义。实验表明某些碳载铂的二元合金可以改善聚合物电解质膜燃料电池中氧还原的电催化性能。本工作的目的是考察ＰｔＣｒ／Ｃ作为氧电极催化剂的活性。采用松木碳为载体和水合肼为还原剂，通过化学还原沉积法制得Ｐｔ／Ｃ和ＰｔＣｒ／Ｃ催化剂。通过涂层和热压得到催化剂－Ｎａｆｉｏｎ膜电极。用电流－电位极化和恒电流放电法研究了催化剂－Ｎａｆｉｏｎ膜电极的性能。与Ｐｔ／Ｃ－Ｎａｆｉｏｎ膜电极比较，ＰｔＣｒ／Ｃ－Ｎａｆｉｏｎ膜电极对氧的电化学还原显示出高的活性。热处理催化剂的活性比未热处理的高。ＸＲＤ分析结果表明，热处理催化剂活性的提高看来主要是由晶格结构改变的结果引起的。

Electrocatalytic activity of PtCr/C Nafion membrane oxygen electrodes

The investigation of oxygen reduction electrocatalysts is of great importance in the advancement of polymer electrolyte membrane fule cell(PEMFC)technology.The tests indicated an improved electroca talytic oxygen reduction performance for some binary platinum alloys supported on carbon in a PEMFC.The purpose of this investigation was to explore the activity of PtCr/C as a catalyst for oxygen electrodes.The Pt/C and PtCr/C catalysts were prepared by chemical reduction deposition,using pine carbon as support and hydrazine hydrate as reducing agent.The catalyst Nafion membrane electrodes were obtained by coating and hot pressing.Performances of the catalyst Nafion membrane electrodes were studied by means of current potential polarization and galvanostatic discharge.Compared with Pt/C Nafion membrane electrodes,PtCr/C Nafion membrane electrodes exhibited high activity for the electrochemical reduction of oxygen.The activity of heat treatment catalysts was higher than that of the unheated one.Results of XRD analysis showed that the enhanced activity of heated catalysts appears to be primarily as a consequence of change in the lattice structure.