Study of degradation and spatial performance of low Pt-loaded proton exchange membrane fuel cells under exposure to sulfur dioxide in an oxidant stream

JOURNAL OF POWER SOURCES

卷:458

Article

Reshetenko, Tatyana¹  Laue, Vincent²  Krewer, Ulrike²  Artyushkova, Kateryna³ 

[1] Univ Hawaii, Hawaii Nat Energy Inst, Honolulu, HI 96822 USA

[2] Tech Univ Carolo Wilhelmina Braunschweig, Inst Energy & Proc Syst Engn, Franz Liszt Str 35, D-38106 Braunschweig, Germany

[3] Univ New Mexico, Dept Chem & Biol Engn, Albuquerque, NM 87106 USA

关键词: PEMFC;    Airborne contaminant;    SO2 poisoning;    Low-Pt cathode;    Segmented cell;   

DOI  :  10.1016/j.jpowsour.2020.228032

来源: Elsevier

【 摘 要 】

Sulfur dioxide is a common air pollutant that has an adverse impact on proton exchange membrane fuel cells (PEMFCs). The present study reports the spatial performance and degradation of low-Pt PEMFCs exposed to trace concentrations of SO2 in a cathode feed stream. PEMFCs exposed to 2 ppm SO2 resulted in a performance loss of 240 and 345 mV for constant current holds of 0.2 and 0.8 A cm(-2). However, the SO2 contamination of low-Pt fuel cells at 1.0 A cm(-2) led to a drastic cell potential drop below 0.1 V from the initial 0.605 V and demonstrated that the cathode exposure to SO2 should be limited to concentrations significantly below 2 ppm for high power operating conditions. The observed voltage and spatial current behavior was attributed to the reduction of SO2 on Pt to zero-valent sulfur at potentials below 0.6 V. PEMFCs recovered performance only after potential cycling, insuring the oxidation of the formed S-0 species at potentials higher than 0.8 V. A comparison of the electrochemical parameters before and after PEMFC poisoning revealed a substantial decrease in electrochemical surface area of up to 45.2% and a final performance loss of 60-100 mV.

【 授权许可】

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