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Studies on PEMFC Stack for SO 2 Contamination at Air Cathode
Author(s) -
Prithi J. A.,
Sasank Viswanath B.,
Rajalakshmi N.,
Dhathathreyen K. S.
Publication year - 2017
Publication title -
fuel cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.485
H-Index - 69
eISSN - 1615-6854
pISSN - 1615-6846
DOI - 10.1002/fuce.201600118
Subject(s) - stack (abstract data type) , proton exchange membrane fuel cell , sulfur , cathode , platinum , adsorption , contamination , chemistry , sulfur dioxide , polarization (electrochemistry) , membrane , chemical engineering , inorganic chemistry , catalysis , organic chemistry , ecology , biochemistry , computer science , engineering , biology , programming language
Sulfur dioxide (SO 2 ) is a common atmospheric contaminant which has a deleterious effect on performance of fuel cells. In the present paper, we are reporting the performance of a proton exchange membrane fuel cell (PEMFC) stack exposed to SO 2 as a contaminant, introduced in air stream and the process of recovery. The stack is exposed to a non‐continuous step wise poisoning of 10ppm of SO 2 in air for about 100 minutes. The response of stack to the contaminant exposure is observed to understand the immediate effect of SO 2 on stack performance and its distribution profile among individual cells. Successive polarization recovery technique, by cycling between two voltages, is adopted to recover the stack after contamination. The sulfur adsorption onto platinum can also be associated to weak and strong adhesion of sulfur species leading to drop in catalyst utilization. The recovery suggests that the sulfur is irreversibly adsorbed on to platinum sites at low current density regions. However, at higher current densities, in the presence of H 2 O, this undergoes rapid hydrolysis to form H 2 SO 4 , leading to partial recovery. The recovered performance of the stack is also presented.