Structure Analysis of PEMFC Cathode Catalyst Layer

Authors

Rui-Qing Wang, Fuel Cell Institute, School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai 200240, China;
Sheng Sui, Fuel Cell Institute, School of Mechanical and Power Engineering, Shanghai Jiaotong University, Shanghai 200240, China;Follow

Corresponding Author

Sheng Sui(ssui@sjtu.edu.cn)

Abstract

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum particle structure in the Pt-rich layer near the proton exchange membrane could promote the ORR rate, while the Pt-poor layer near the gas diffusion layer had higher porosity and average pore size, which is beneficial to the reaction gas transmission and diffusion. When the platinum loading ratio of the rich to poor platinum layer was 1:2, the best single cell performance was achieved. The current density at 0.6 V reached 1.05A·cm^-2, and the maximum power density was 0.69 W·cm^-2. Compared with the single-layer structure, the peak power density was increased by 21%. When growing Pt-NWs on the Pt-NPs base layer, the presence of Pt particles promoted the reduction of platinum precursors and provided deposition sites for newly formed Pt atoms, and the grown Pt-NWs had a more uniform distribution as well as a denser pile structure. The current density of the optimized Pt-NWs catalytic layer structure at 0.6 V increased by 21%. The MEA fabricated by double-catalytic layer method had a higher catalyst utilization rate and a guiding significance for the optimization of the cathode catalytic layer structure. The high activity shown by the platinum nanowires provides a new idea for the preparation of efficient catalysts.

Graphical Abstract

Keywords

proton exchange membrane fuel cell, double-layer catalytic layer, membrane electrode assembly, cathode, platinum nanowires

DOI Link

https://doi.org/10.13208/j.electrochem.201208

Publication Date

2021-12-28

Online Available Date

2021-01-11

Revised Date

2020-12-29

Received Date

2020-12-08

Recommended Citation

Rui-Qing Wang, Sheng Sui. Structure Analysis of PEMFC Cathode Catalyst Layer[J]. Journal of Electrochemistry, 2021 , 27(6): 595-604.
DOI: The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum particle structure in the Pt-rich layer near the proton exchange membrane could promote the ORR rate, while the Pt-poor layer near the gas diffusion layer had higher porosity and average pore size, which is beneficial to the reaction gas transmission and diffusion. When the platinum loading ratio of the rich to poor platinum layer was 1:2, the best single cell performance was achieved. The current density at 0.6 V reached 1.05A·cm^-2, and the maximum power density was 0.69 W·cm^-2. Compared with the single-layer structure, the peak power density was increased by 21%. When growing Pt-NWs on the Pt-NPs base layer, the presence of Pt particles promoted the reduction of platinum precursors and provided deposition sites for newly formed Pt atoms, and the grown Pt-NWs had a more uniform distribution as well as a denser pile structure. The current density of the optimized Pt-NWs catalytic layer structure at 0.6 V increased by 21%. The MEA fabricated by double-catalytic layer method had a higher catalyst utilization rate and a guiding significance for the optimization of the cathode catalytic layer structure. The high activity shown by the platinum nanowires provides a new idea for the preparation of efficient catalysts.