Reconstruction and optimization of catalyst layer of high temperature proton exchange membrane fuel cell

Catalyst layer determines the performance and cost of high temperature proton exchange membrane fuel cell. However, a fundamental understanding and optimization of its microstructure is hindered by the characterization limitation. In this study, the micro model and macro model are integrated to examine the effects of ionomer/carbon (I/C) ratio, Pt/C ratio and Pt loading on the microstructure and cell performance. As many Pt particles are partly coved by the ionomer, assuming all catalyst are covered by ionomer is inappropriate. Both Pt/C ratio and I/C ratio can significantly affect the compositions and microstructure of CL. The increase of Pt loading increases the cell performance, but the increment is small at a high platinum loading. However, the performance cost increases linearly with the increasing platinum loading. Thus, both cell performance and performance cost must be taken into consideration when designing CL of high temperature proton exchange membrane fuel cell. • The micro model and macro model were integrated for study. • I/C ratio, Pt/C ratio and Pt loading were examined. • Triple phase boundary of HT-PEMFC was quantified. • The coverage degree of catalyst by ionomer were studied.