Comparison studies between fibers and carbon nanotubes doped with nitrogen.

摘要

One of challenges in the commercialization of fuel cells is the high production cost and scarcity of platinum based catalysts. Several studies propose solutions based on the decrease of platinum amount; e.g. enhance the support and dispersion, decreasing their particle size, combine with other metals, etc. Recendy, systems based on carbon nanostructures have been proposed as a good option to solve the precious metal problem. They have been studied, either as supporting material adding interesting properties to the active metals, or only as doped carbon nanostructures using heteroatoms (i.e. N, B, S), creating Pt-free electrocatalysts. Since 2009, Dai et al. reported a different path to synthesize electrocatalysts, using nitrogen doped carbon nanotubes, creating a branch of metal-free catalysts with activities very close to platinum for ORR [1]. Recent studies are shifting towards to carbon derivatives with a graphitic lattice limited, such as activated carbon, carbon black, carbon fibers and amorphous graphite doped with nitrogen, offering economic advantages due to its simplicity in the synthesis [2].