Single-Step Fabrication of a Multiscale Porous Catalyst Layer by the Emulsion Template Method for Low Pt-Loaded Proton Exchange Membrane Fuel Cells
Sun-Gyu Choi, Sun-Gyu Choi, Jiyoon Jeon, Junsu Chae, Seongmin Yuk, Donghyun Lee, Gisu Doo, Dong Wook Lee, Jonghyun Hyun, Jiyun Kwen, Siyoung Q. Choi, Siyoung Q. Choi, Hee‐Tak Kim
Abstract
Multiscale porosity assures better mass transport for a low Pt-loaded fuel cell; however, achieving a complex pore structure in a simple manner presents a major challenge. In this work, by using the emulsion template method, a multiscale porous catalyst layer with macro- and mesopores was fabricated in a single step. A stable high internal phase emulsion is achieved with catalyst layer components by exploiting a Nafion ionomer as a surfactant. The oil phase of the emulsion catalyst slurry induces the macropores, and the Pt/C and ionomer mixture in the hydrophilic solvent forms a mesoporous framework in the catalyst layer. Scanning electron microscopy and micro X-ray computed tomography confirmed the formation of uniform and well-interconnected macropores. The performance of the low Pt-loaded catalyst layer derived from the emulsion template method considerably improved the mass transport property due to the mitigation of water flooding. The fabrication of an emulsion-based catalyst layer provides an efficient platform to design high-performance low Pt-loaded fuel cells.