Influence of platinum dispersity on oxygen transport resistance and performance in PEMFC. (1st February 2020)

• Record Type: Journal Article
• Authors: Sun, Xinye; Yu, Hongmei; Zhou, Li; Gao, Xueqiang; Zeng, Yachao; Yao, Dewei; He, Liang; Shao, Zhigang
• Is Part Of: Electrochimica acta. Volume 332(2020)
• Publication Date: 2020-02-01
• Subjects: Pt dispersity -- Local oxygen transport resistance -- Catalyst layer thickness -- Mass transport resistance analysis; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.135474
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Platinum dispersity on the carbon support is first shown as a factor of local oxygen transport resistance in this work, while its impact on PEMFC performance is also analyzed. The dispersity of platinum is defined as the distribution density of Pt particles on the surface of carbon supports. In order to exclude the influence of catalyst layer thickness, different platinum dispersity cathode catalyst layers are prepared by mechanical mixing Pt/C with different mass ratios, different Pt loadings with the same amount of Pt and carbon in the MEAs to keep the thickness of catalyst layers consistent. Initial fuel cell performance is much higher with lower Pt dispersity. Oxygen transport resistance is measured through limiting current density method, and the total oxygen transport resistance R total, Fick diffusion resistance R F, and local oxygen transport resistance R are calculated. All of them increase at higher Pt dispersity. Platinum dispersity shows obvious influence both on performance and oxygen transport resistance. Thus, increasing the ratio of platinum particles distributed at the surface of carbon supports and the density of platinum particles on carbon supports can be effective ways to solve the problem of performance loss with low Pt loading at high current densities. Highlights: Explore an important factor of local oxygen transport resistance – Pt dispersity. Investigate the influence of Pt dispersity on MEA performance. Verify the great influence of water film on local oxygen transport resistance.