文献类型：期刊文献

英文题名：A microreactor with superhydrophobic Pt–Al2O3 catalyst coating concerning oxidation of hydrogen off-gas from fuel cell

作者：Yu, Wei[1]; Tao, Jiabo[3]; Yu, Xinhai[1,2]; Zhao, Shuangliang[3]; Tu, Shan-Tung[1]; Liu, Honglai[3]

机构：[1] Key Laboratory of Pressure Systems and Safety [MOE], School of Mechanical Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; [3] State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, China

年份：2017

卷号：185

起止页码：1233

外文期刊名：Applied Energy

收录：EI(收录号：20160601899457)

语种：英文

外文关键词：Alumina - Hydrophobicity - Aluminum oxide - Flow patterns - Grafting (chemical) - Oxidation - Polyelectrolytes - Proton exchange membrane fuel cells (PEMFC) - Catalyst activity - Microchannels - Coatings

摘要：For polymer electrolyte fuel cells (PEFCs), Pt–Al2O3 catalyst coatings were developed to convert hydrogen off-gas of PEFCs to water. To ignite the hydrogen oxidation at room temperature with negligible induction period, the Pt–Al2O3 catalyst coatings on the walls were modified from hydrophilicity to superhydrophobicity via grafting by 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FAS). The modified Pt–Al2O3 catalyst coatings were optimized in a channel plate reactor (CPR) that is similar to microchannel reactors in flow pattern, but is much simpler to be fabricated and can be used repeatedly. We showed that higher grafting density of FAS provided stronger repulsive force on produced water vapor (favorable effect) while more resistance for the reactants approaching to catalytic active sites (unfavorable effect). The suitable hydrophobic modification significantly promoted the catalytic activities and stabilities of the catalyst coatings under both humid and dry feed stream conditions. Under the humid feed stream condition, the most active catalyst coating of 5WM-Pt–Al2O3 showed the biggest contact angle of 150° and decreased the hydrogen concentration from 4 vol% to 632 ppm without a detectable induction period at 303 K. The microchannel reactor with superhydrophobic catalyst coatings showed great potential for conversion of hydrogen off-gas of PEFCs to water. ? 2016 Elsevier Ltd