The influence of relative humidity on the performance of fuel cell catalyst layers in ethanol sensors

详细信息    查看全文

• 作者：Jesse T.S. Allan ; ^{Jesse.Allan@uoit.ca" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Mohammad R. RahmanAuthor Vitae ; E. Bradley Easton ^{Brad.Easton@uoit.ca" class="auth_mail" title="E-mail the corresponding author}Author Vitae
• 关键词：Breath alcohol sensor ; Ethanol testing station ; Fuel cell sensors ; Direct alcohol fuel cell ; Relative humidity
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：239
• 期：Complete
• 页码：120-130
• 全文大小：3448 K

文摘

The influence of relative humidity (RH) on the sensing performance of two commercially available fuel cell catalysts were investigated in an ethanol sensor device. Two sets of sensor membrane electrode assemblies (MEAs) were prepared using platinum black (Pt) and 20% platinum supported on carbon (Pt/C). One set employed a Nafion membrane, while the second set employed a porous polyvinyl chloride (PVC) membrane containing sulfuric acid, the latter of which is commonly used in commercial ethanol sensor MEAs. Using our advanced fuel cell sensor testing station, the sensing performance of each set of MEAs was measured and compared with that of a commercial breath alcohol sensor (BrAS) MEAs. It was found that both the Pt and Pt/C outperformed the commercial materials regardless of membrane. The Pt/C-Nafion MEA outperformed the Pt-Nafion MEA both in raw performance at both high humidity and low humidity. The change in sensitivity from 95% RH to 45% RH for the Pt/C-Nafion MEA was also lower compared to the Pt-Nafion MEA. As smaller change in sensitivity would indicate better stability. The porous nature of the Pt/C catalyst reduces the likelihood of flooding at the interface. The Pt/C-PVC MEA outperformed the Pt-PVC MEA in raw performance, but the stability of the Pt-PVC was superior. This was due to the small porosity of the Pt, which reduces water loss in the lower relative humidity environment.