Recently, Prof. Michael. D. Guiver and Prof. Yan Yin at the State Key Laboratory of Engines, cooperated with Prof. Dario R. Dekel from Technion – Israel Institute of Technology, published their new research, titled Multi-scale study on bifunctional Co/Fe‒N‒C cathode catalyst layers with high active site density for the oxygen reduction reaction, in Applied Catalysis B: Environmental. The regulation of bimetal active sites and multi-scale evaluation strategy of catalyst or catalyst layer for fuel cell were discussed in this paper.

The cathode catalyst layer of fuel cell faces many problems, such as low density of active sites and incomplete evaluation methods. To further improve the performance of fuel cells, CoFe nanoalloy catalyst with high active site density was prepared by adjusting the proportion of Co and Fe elements in catalyst precursor. In addition, the synergistic catalytic effect of nanoalloy and single atom was verified by physical and chemical characterization, as well as density functional theory calculation.

A multi-scale evaluation of catalyst, catalyst layer and membrane electrode assembly was conducted by rotating disk electrode (RDE), half cell and single cell setups, respectively. This strategy provides a comprehensive understanding, from simple to complex and from material to fuel cell device. During half-cell test, the loading and microstructure of the catalyst layer can simulate the conditions of a single cell test. Coupled with efficient oxygen transport, the half cell can obtain more accurate performance data of the catalyst layer within the working range of the fuel cell (0.6‒0.8V). It fills the understanding gap between RDE (catalyst test) and single cell test (membrane electrode assembly test).

The multi-scale strategy provides more accurate theoretical guidance for fuel cell catalyst development. Weikang Zhu is the first author of the research paper, and Dr. Junfeng Zhang, Prof. Yan Yin, and Prof. Dario R. Dekel are the corresponding authors.

By the School of Mechanical Engineering

Editor: Eva Yin