Single Atom and Hierarchical Pore Aerogel Confinement Strategy for Low-platinum Fuel CellSingle Atom and Hierarchical Pore Aerogel Confinement Strategy for Low-platinum Fuel Cell.

Abstract

Achieving high catalytic performance through the lowest possible content of platinum (Pt) is the key to cost reduction of proton exchange membrane fuel cells (PEMFCs). However, lowering the Pt loading in PEMFCs leads to high mass transport resistance of oxygen originated from the limited accessible active sites, and cause less stability of loaded ultrafine Pt nano-catalyst due to substantial size growth in long-term operations. Herein, we design new Pt-metal/metal-N-C aerogel catalyst that substantially reduces oxygen-related mass transport resistance and has long-term durability. The tailor of the Fe-N-C aerogel support with hierarchical and interconnecting pores enable a low local oxygen transport resistance (0.18 s/cm) for fuel cell with ultra-low Pt loading (50 ± 5μg Pt /cm2 ). Chemical confinement of Fe-N sites in Fe-N-C aerogel ensure high stability of the loaded-Pt both in the processes of high temperature synthesis up to 1000°C and practical application as fuel cell catalyst. The ultra-low Pt fuel cell displays a low voltage loss of 8mV at 0.80 A/cm2 and unchanged electrochemical surface area after 60, 000 cycles of accelerated durability test. The allied of hierarchical pore, aerogel and single atom can fully reflect their structural advantages and expand the understanding for the synthesis of advanced fuel cell catalysts. This article is protected by copyright. All rights reserved.