NANOSTRUCTURED CARBONS AND THEIR HIERARCHICAL ASSEMBLY: NOVEL METAL CATALYST SUPPORTS FOR FUEL CELLS

摘要

The catalyst supports have a significant influence on the performance of metal catalysts using in low temperature fuel cells. Recently, there are increasing interests in the study of nanostructured carbon materials as catalyst supports. Our report will be divided into two parts. In the first part, through X-ray diffraction, analytical electron microscopy and electrochemical analysis, we try to establish a relationship between nanostructures of carbon supports and the electrochemical properties of supported metal catalysts (such as intrinsic catalytic activity, utilized efficiency and mass transport). In the second part, hierarchically assembled carbon nanostructures are demonstrated as novel catalyst supports. Carbon nanotubes, carbon nanosheets etc. are grown directly on various carbon substrate materials (carbon blacks, carbon spheres and carbon fibers etc.) to form hierarchical structures. The great benefit of such hierarchical structures is to combine the advantages of carbon nanostructures (good conductivity, large surface area, etc.) and carbon substrate materials (mesopores and macropores can provide fast mass transport) on a multiscaled space, thus maximally improve the fuel cell performance.