- Bio-mimetic carbon nanotube competes with platinum in fuel cell technology -
Cathodic oxygen reduction reaction (ORR) is the rate-limiting step for low-temperature fuel cells such as proton-exchange membrane and direct methanol fuel cells. To expedite the rate-limiting ORR for practical power applications, one has to use a large amount of platinum (Pt) as a catalyst. At the moment, Pt is the only meaningful ORR catalyst in industry. However, Pt is very costly and rare. Also it is not stable for extensive use. Here, from collaborative efforts of theory and experiment, we report a new, biomimetic carbon nanotube-based material as an excellent and extremely stable ORR catalyst that could compete Pt in fuel cell technologies. The novel material is a kind of composite between catalytic Fe-porphyrins and electron conducting carbon nanotubes. The facile plasma-enhanced CVD synthesis of the material is justified with photoemission spectroscopies and electrochemical ORR half-cell experiments, as well as density-functional theory calculations. This nano-bio hybrid catalyst would not impact only on fuel-cell technologies, but also, taking advantage of functional diversities of metal-porphyrin complexes and carbon nanotubes/graphenes, metal-porphyrin incorporated carbon nanotubes or graphenes could have significant implications in various emerging nano-technologies, including sensors, energy storage, solar cells, artificial photosynthesis, and nano-biomedical applications.
