Recent advances of Fe single atom catalysts towards high-performance proton exchange membrane fuel cells

The Fe–N–C catalysts with atomic Fe1 active sites are the most active low-cost alternatives to Pt/C for the large-scale application of proton exchange membrane fuel cells (PEMFCs). However, the activity performance of Fe–N–C catalysts still lags behind that of Pt catalysts, especially in PEMFC devices. This review focuses on the three key factors affecting the activity of Fe–N–C catalysts and the advanced synthesis strategies for high-performance Fe–N–C. Based on the literature data, we have summarized the relationship between catalyst iron content and effective site concentration, pointed out the current difficulties encountered in catalyst design, and proposed several aspects that future research needs to focus on. We believe this review could guide the rational design of Fe–N–C type of single-atom catalysts and promote the development of low-cost PEMFCs.