Chemical vapour deposition of Fe–N–C oxygen reduction catalysts with full utilization of dense Fe–N4 sites

Li Jiao (1) , Jingkun Li (2) , Lynne Larochelle Richard , Qiang Sun , Thomas Stracensky , Ershuai Liu , Moulay Tahar Sougrati (2) , Zipeng Zhao , Fan Yang , Sichen Zhong , Hui Xu , Sanjeev Mukerjee , Yu Huang , David A Cullen , Jae Hyung Park , Magali Ferrandon (3) , Deborah J Myers (3) , Frédéric Jaouen (2) , Qingying Jia (1)

1 Northeastern University [Boston]
2 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
3 ANL - Argonne National Laboratory [Lemont]

Replacing scarce and expensive platinum (Pt) with metal-nitrogen-carbon (M-N-C) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) has largely been impeded by the low activity of M-N-C, in turn limited by low site density and low site utilization. Herein, we overcome these limits by implementing chemical vapor deposition (CVD) to synthesize Fe-N-C, an approach fundamentally different from previous routes. The Fe-N-C catalyst, prepared by flowing iron chloride vapor above a N-C substrate at 750 , has a record Fe-N4 site density of 2×10 20 sites•gram-1 with 100% site utilization. A combination of characterizations shows that the Fe-N4 sites formed via CVD are located exclusively on the surface, accessible by air, and electrochemically active. This catalyst delivers an unprecedented current density of 33 mA•cm-2 at 0.90 ViR-free (iR-corrected) in an H2-O2 PEMFC at 1.0 bar and 80 .

Domaines: Matériaux; Catalyse

Li Jiao, Jingkun Li, Lynne Larochelle Richard, Qiang Sun, Thomas Stracensky, et al.. Chemical vapour deposition of Fe–N–C oxygen reduction catalysts with full utilization of dense Fe–N4 sites. Nature Materials, 2021, 20, pp.1385-1391. ⟨10.1038/s41563-021-01030-2⟩. ⟨hal-03361325⟩