Jang, Jeonghee Sharma, Monika Choi, Daeil Kang, Yun Sik Kim, Youngjin Min, Jiho Sung, Hukwang Jung, Namgee Yoo, Sung Jong 2024-01-19T19:31:43Z 2024-01-19T19:31:43Z 2021-09-02 2019-08-07 1944-8244 https://pubs.kist.re.kr/handle/201004/119688 Performance degradation generated by reverse current flow during fuel cell shut-down/start-up is a big challenge for commercialization of polymer electrolyte membrane fuel cells in automobile applications. Under transient operating conditions, the formation of H-2/O-2 boundaries on Pt surfaces and the occurrence of undesired oxygen reduction reaction (ORR) in an anode cause severe degradation of carbon supports and Pt catalysts in a cathode because of an increase of the cathode potential up to similar to 1.5 V. Herein, to directly prevent the formation of H-2/O-2 boundaries in the anode, we propose a unique metal-carbon hybrid core-shell anode catalyst having Pt nanoparticles encapsulated in nanoporous carbon shells for selective H-2 permeation. This hybrid catalyst exhibits high hydrogen oxidation reaction (HOR) selectivity along with fully subdued ORR activity during long-term operation because of the excellent stability of the carbon molecular sieves. Furthermore, the HOR-selective catalyst effectively suppresses the reverse current flow in a single cell under shut-down/start-up conditions. English American Chemical Society OXYGEN REDUCTION REVERSE-CURRENT START-UP PLATINUM GRAPHENE PEMFC OXIDE STABILITY ELECTRODE SUPPORT Boosting Fuel Cell Durability under Shut-Down/Start-Up Conditions Using a Hydrogen Oxidation-Selective Metal-Carbon Hybrid Core-Shell Catalyst Article 10.1021/acsami.9b06309 1 ACS Applied Materials & Interfaces, v.11, no.31, pp.27735 - 27742 ACS Applied Materials & Interfaces 11 31 27735 27742 scie scopus 000480498600026 2-s2.0-85070565991 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article OXYGEN REDUCTION REVERSE-CURRENT START-UP PLATINUM GRAPHENE PEMFC OXIDE STABILITY ELECTRODE SUPPORT durability hydrogen oxidation reaction polymer electrolyte membrane fuel cells reverse current selectivity