碳载体对PtRu/C催化剂性能的影响研究

本文采用水热方法合成不同粒径和形貌的碳球,并将其作为载体,采用化学镀的方法制备PtRu/C催化剂;应用XRD、SEM和TEM对碳球及催化剂的结构和形貌进行表征。采用电化学方法测试不同形貌碳球的比表面积以及碳球担载催化剂的催化活性,结果表明,水热反应条件对碳球的粒径及形貌影响显著,三种碳球担载催化剂的活性按照以下顺序衰减：多孔的粒径约为100nm的碳球担载PtRu催化剂优于连体碳球优于直径约500nm的单分散碳球担载催化剂。TEM分析结果表明,在碳球表面化学镀的PtRu纳米颗粒均匀分散在碳载体表面,其平均粒径约为3nm。电化学测试表明粒径为100nm的多孔碳球的电化学比表面积较大,以这种碳球为载体的PtRu/C催化剂对甲醇氧化的催化性能较高。

Effects of the morphology and structure of carbon spheres on the performance of PtRu/C catalysts for methanol oxidation

Three kinds of carbon materials synthesized by a hydrothermal method with different diameters and morphologies are selected as the support of PtRu catalysts for direct methanol fuel cells （DMFC）. The structure and morphology of the carbon supports and the catalysts are characterized by XRD, SEM and TEM. The specific surface areas of the carbon nanospheres and the electro-catalytic activity of the catalysts supported on different carbon nano/microspheres are evaluated by electrochemical measurements. The results show that the activity of the three different catalysts follow the descending order： carbon nanospheres with the diameter of 100 nm, siamesed carbon spheres with the diameter of 200 nm （for each sphere）, carbon microspheres with the diameter of 500 nm, agreed with their sequence of the specific surface areas and the electronic conductivity. The results display that relative high specific surface areas of carbon nanospheres led to a high activity for methanol oxidation.