Low-Pt and Pt-free Catalysts for Oxygen Reduction Reaction in PEM Fuel Cells

As clean and sustainable energy conversion devices, PEM fuel cells (PEMFCs) are expected to play dominant role in future clean energy solutions for various applications. However, the high cost of Pt catalyst is one of the main obstacles for the wide-spread commercialization of PEMFCs. Therefore, developing highly efficient low-Pt and Pt-free catalysts are the key to solve the above-mentioned challenges. In this talk, I will present our recent progress in developing advanced electrocatalysts mainly for oxygen reduction reaction (ORR) in PEMFCs. Among the non-precious-metal (Pt-free) catalysts, Fe/N/C catalysts are considered one of the most promising ORR catalysts. One major breakthrough has been made by Dodelet et al, with activity and performance of Fe/N/C catalyst approaching to that of Pt [1,2]. However, the durability of Fe/N/C catalysts is still insufficient for practical applications and its performance decay mechanism is still unclear. Very recently, in collaboration with Dodelet, we made a systematic study to verify whether iron is at the origin of the first rapid decay (stability problem) of the Fe/N/C catalyst for ORR in PEMFCs, which is important to find better ways to improve the durability of Fe/N/C catalysts [3]. Moreover, a new type of 3D porous carbon based Fe/N/C catalyst will be discussed, which shows excellent activity and stability for ORR in both acidic and alkaline media. At the same time, a series of novel Pt nanostructured (low-Pt) electrocatalysts, including nanowires, nanotubes and single atoms, for fuel cells will also be discussed [4-8].