氮功能化碳纳米管载Pt及碳载PtSnCo燃料电池催化剂研究化学工程与技术专业论文.docxVIP

重庆大学硕士学位论文英文摘要 重庆大学硕士学位论文 英文摘要 PAGE PAGE IV ABSTRACT Fuel cell converting chemical energy directly into electrical energy with high efficiency and low emission of pollutants may help to reduce environmental impact. Fuel cell is a practical answer to the worlds pressing need for clean and efficient power. For decades, Pt-based catalysts are widely used in catalysis of oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). However, the drawbacks with use of platinum, limited supply, high cost and easily poisoned by trace of carbon monoxide limit its use. Thus, a great effort has been devoted to development of new fuel cell electro-catalysts in order to increase Pt activity and reduce platinum consumption. At the same time, platinum-free catalysts have been highly esteemed. CNTs as a new form of carbon, have received researchers’ attention due to their unique structural, electronic and mechanical properties. The use of CNTs as alternative supports for preparation of catalysts for low-temperature fuel cells has naturally stimulated significant interest among researchers. In recent years there has been a progress in the understanding of that the catalyst-support interaction plays a fundamental role in the performance of catalyst. However, the effective attachment of uniformly dispersed Pt nanoparticles remains a formidable challenge, due to the inertness and hydrophobic properties of the CNT surface. In part I of this paper, we successfully introduce N atoms to the graphite structure of CNTs by a simple and efficient method, leading to a certain amount of chemically active impurity sites and less surface oxygen groups. The platinum supported on nitrogen functionalized carbon nanotubes catalysts were prepared by a simple NaBH4 reduction method. We studied its electrochemical properties by electrochemistry measurement. The catalysts were characterized X-ray diffraction (XRD), transmission electron microsc