Iron Single Atoms on Graphene as Nonprecious Metal Catalysts for High-Temperature Polymer Electrolyte Membrane Fuel Cells

Yi Cheng; Shuai He; Shanfu Lu; Jean-Pierre Veder; Bernt Johannessen; Lars Thomsen; Martin Saunders; Thomas Becker; Roland De Marco; Qingfeng Li; Shi-Ze Yang; San Ping Jiang

doi:10.1002/advs.201802066

Iron Single Atoms on Graphene as Nonprecious Metal Catalysts for High-Temperature Polymer Electrolyte Membrane Fuel Cells

Adv Sci (Weinh). 2019 Mar 13;6(10):1802066. doi: 10.1002/advs.201802066. eCollection 2019 May 17.

Authors

Yi Cheng¹, Shuai He², Shanfu Lu³, Jean-Pierre Veder⁴, Bernt Johannessen⁵, Lars Thomsen⁵, Martin Saunders⁶, Thomas Becker⁷, Roland De Marco^{8

9}, Qingfeng Li¹⁰, Shi-Ze Yang¹¹, San Ping Jiang²

Affiliations

¹ Department of Environmental Engineering School of Metallurgy and Environment Central South University Changsha 410083 China.
² Fuels and Energy Technology Institute & Western Australia School of Mines: Minerals, Energy and Chemical Engineering Curtin University Perth Western Australia 6102 Australia.
³ Beijing Key Laboratory of Bio-inspired Energy Materials and Devices School of Space and Environment Beihang University Beijing 100191 P. R. China.
⁴ John de Laeter Centre Curtin University Perth Western Australia 6102 Australia.
⁵ Australian Synchrotron Clayton Victoria 3168 Australia.
⁶ Centre for Microscopy Characterization and Analysis (CMCA) and School of Molecular Sciences The University of Western Australia Perth Western Australia 6009 Australia.
⁷ School of Molecular and Life Sciences/Curtin Institute of Functional Molecules and Interfaces Curtin University Perth Western Australia 6102 Australia.
⁸ Faculty of Science, Health, Education and Engineering University of Sunshine Coast Maroochydore DC Queensland 4558 Australia.
⁹ School of Chemistry and Molecular Biosciences The University of Queensland Brisbane Queensland 4072 Australia.
¹⁰ Department of Energy Conversion and Storage Technical University of Denmark Lyngby 2800 Denmark.
¹¹ Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA.

Abstract

Iron single atom catalysts (Fe SACs) are the best-known nonprecious metal (NPM) catalysts for the oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cells (PEMFCs), but their practical application has been constrained by the low Fe SACs loading (<2 wt%). Here, a one-pot pyrolysis method is reported for the synthesis of iron single atoms on graphene (FeSA-G) with a high Fe SAC loading of ≈7.7 ± 1.3 wt%. The as-synthesized FeSA-G shows an onset potential of 0.950 V and a half-wave potential of 0.804 V in acid electrolyte for the ORR, similar to that of Pt/C catalysts but with a much higher stability and higher phosphate anion tolerance. High temperature SiO₂ nanoparticle-doped phosphoric acid/polybenzimidazole (PA/PBI/SiO₂) composite membrane cells utilizing a FeSA-G cathode with Fe SAC loading of 0.3 mg cm^-2 delivers a peak power density of 325 mW cm^-2 at 230 °C, better than 313 mW cm^-2 obtained on the cell with a Pt/C cathode at a Pt loading of 1 mg cm^-2. The cell with FeSA-G cathode exhibits superior stability at 230 °C, as compared to that with Pt/C cathode. Our results provide a new approach to developing practical NPM catalysts to replace Pt-based catalysts for fuel cells.

Keywords: high loading; high temperature polymer electrolyte membrane fuel cells; iron single atom catalysts; nonprecious metal catalysts; oxygen reduction reaction.