(523a) Porous Structure Based High Performance Electrocatalysts for Low Temperature Fuel Cells

In this presentation, a simple and scalable method to produce ordered-intermetallic FePt nanotubes by electrospinning will be presented. When tested at cathode catalysts, under the US Department of Energy’s reference condition, the activity of face-centered-tetragonal (fct) FePt NTs surpasses that of commercial Pt/C. In an accelerated degradation test at 1.4 V for 3h, the degradation activity rate of fct-FePt NTs is only 10%, whereas that of commercial Pt/C catalysts is 65%. This approach would provide simple route to support-free intermetallic nanotube structure with superior kinetic activity and higher durability than those of commercial Pt/C catalyst. I will also present the effect of the pore size and doping site position on the single-cell performance of metal-free catalysts using wee-defined ordered mesoporous carbon systems. Well-defined large pore sized mesoporous carbons were synthesized by simple self-assembly of block copolymers with carbon and silicate precursors. The single-cell tests prove that control of pore size and doping-site positon directly affects the cell performance by changing the mass-transport properties and utilizing the doping sites in the catalyst layer. NPOMC with precisely controlled doping sites to be near the large mesopores exhibited a remarkable on-set potential and achieved 70% of the maximum power density of Pt/C. The high performance metal alloy based CO₂ reduction electrocatalysis will be also presented.