一步微波有机溶胶法制备燃料电池Pt/C电催化剂

采用一步微波有机溶胶法制备了系列20%Pt/C燃料电池催化剂。考察了不同硝酸浓度氧化处理碳粉的表面、微波反应时间以及还原剂乙二醇(EG)的用量等因素对催化剂电催化活性的影响。实验发现:无论是阳极还是阴极反应,处理碳粉时硝酸浓度为40%、微波反应时间70 s时制备的催化剂活性最好;然而,阳极甲醇氧化时制备催化剂EG用量较少、活性高,阴极氧还原时EG用量较多反而有利。采用X射线衍射(XRD)、透射电镜(TEM)、循环伏安法(CV)等方法对催化剂进行测试。结果表明,不同考察因素对于活性组分的结构、晶型及粒径没有太大影响,但对电化学活性比表面积和电催化活性有显著影响。

Fuel Cell Pt/C Catalyst Prepared by One-Step Microwave Organic Sol Method

The carbon-supported fuel cell platinum catalysts 20%Pt/C were prepared by one-step microwave-colloidal method. The influence of different factors, such as the concentration of nitric acid used in carbon powder catalyst carrier, the microwave reaction time of preparation for the catalysts and the dosage of ethylene glycol reductant on the catalyst electric catalytic activity was compared here. It is found that the activity is the best when the concentration of nitric acid is 40% and the microwave reaction time is 70 second during both anode and cathode reaction. Interestingly, when the catalyst is used for methanol oxidation, lower dosage of EG leads to higher activity, while for oxygen reduction higher dosage of EG is better instead. X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV) etc, revealed that the structure, crystal structure and the particle size did not change much by different preparation conditions whereas the electrochemical special surface area and electric catalytic activity have a significant influence.