TY - JOUR
T1 - Effect of polymer-coating on carbon blacks for Pt utilization efficiency of polymer electrolyte membrane fuel cells
AU - Jayawickrama, Samindi Madhubha
AU - Fujigaya, Tsuyohiko
N1 - Funding Information:
This study was supported in part by the Nanotechnology Platform Project, from the Ministry of Education , Culture, Sports, Science, and Technology ( MEXT ), Japan, KAKENHI (No. JP18H01816 ) from the Japan Society for the Promotion of Science (JSPS), JSPS Bilateral Program (No. AJ190078 ) from JSPS, and CREST (No. AJ199002 ) from Japan Science and Technology Agency (JST), and Fukuoka Financial Group Foundation.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/1/15
Y1 - 2021/1/15
N2 - To reduce the usage of Pt in polymer electrolyte membrane fuel cell electrocatalysts, an increase of the Pt utilization efficiency is crucial. In this study, the effect of polybenzimidazole (PBI) wrapping on carbon blacks (CBs) for the improvement of the Pt utilization efficiency in polymer electrolyte membrane fuel cells is investigated using CBs having a high surface area (HSA) and a low surface area (LSA). Subsequently, the structure-efficiency relationship is determined. A comparison study of the single-cell measurements using PBI-coated and non-coated HSA and LSA electrocatalysts reveals that HSA CB is more effective to improve the Pt utilization efficiency, where an improvement of 33% for the power density is achieved, while LSA CB shows an improvement of 10% under conditions of 80 °C at a relative humidity of 100%. The mechanism behind the greater improvement, especially for HSA CB, is mainly related to the micropore capping by the PBI wrapping, which increases the electrochemical active surface area as well as the proton conductivity and O2 diffusion. However, even though the degree of improvement is lower for LSA CB, an increase of the Pt utilization efficiency is realized mainly owing to the loading of uniformly dispersed smaller Pt.
AB - To reduce the usage of Pt in polymer electrolyte membrane fuel cell electrocatalysts, an increase of the Pt utilization efficiency is crucial. In this study, the effect of polybenzimidazole (PBI) wrapping on carbon blacks (CBs) for the improvement of the Pt utilization efficiency in polymer electrolyte membrane fuel cells is investigated using CBs having a high surface area (HSA) and a low surface area (LSA). Subsequently, the structure-efficiency relationship is determined. A comparison study of the single-cell measurements using PBI-coated and non-coated HSA and LSA electrocatalysts reveals that HSA CB is more effective to improve the Pt utilization efficiency, where an improvement of 33% for the power density is achieved, while LSA CB shows an improvement of 10% under conditions of 80 °C at a relative humidity of 100%. The mechanism behind the greater improvement, especially for HSA CB, is mainly related to the micropore capping by the PBI wrapping, which increases the electrochemical active surface area as well as the proton conductivity and O2 diffusion. However, even though the degree of improvement is lower for LSA CB, an increase of the Pt utilization efficiency is realized mainly owing to the loading of uniformly dispersed smaller Pt.
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U2 - 10.1016/j.jpowsour.2020.228932
DO - 10.1016/j.jpowsour.2020.228932
M3 - Article
AN - SCOPUS:85091586531
SN - 0378-7753
VL - 482
JO - Journal of Power Sources
JF - Journal of Power Sources
M1 - 228932
ER -
