Low temperature synthesis of new highly graphitized N-doped carbon for Pt fuel cell supports, satisfying DOE 2025 durability standards for both catalyst and support
Abstract
For polymer electrolyte membrane fuel cells (PEMFCs), the state-of-the-art electrocatalysts are based on carbon-supported Pt group metals. However, current carbon supports suffer from carbon corrosion during repeated start-stop operations, causing performance degradation. We report a new strategy to produce highly graphitized carbon with controllable N-doping that uses low-temperature synthesis (650 ℃) from g-C₃N₄ carbon-nitrogen precursor with pyrolysis using Mg. The high graphiticity is confirmed by high-intensity 2D Raman peak with low I_D/I_G (0.57), pronounced graphitic XRD planes, and excellent conductivity. Without further post-treatment, this highly graphitized N-doped carbon (HGNC) material combines high pyrrolic-N content with high porosity. Supporting Pt on HGNC exhibits excellent oxygen reduction activity for PEMFC with greatly improved durability as proved by real-time loss measurements of Pt and carbon, the first to surpass the DOE 2025 durability targets for both catalyst and support. The Pt/HGNC-65 shows 32% and 24% drop in mass activity after accelerated durability tests of both electrocatalyst and support, respectively, which are less than DOE target of 40% loss. The atomistic basis for this durability is explained via quantum mechanics-based molecular dynamics simulations. Interestingly, it is found that pyrrolic-N strongly interacts with Pt, making the Pt catalyst more stable during fuel cell reaction.
Additional Information
This work was generously supported by NRF grant (NRF-2019R1A2C2086770 and NRF-2019M3A6A7023742) funded by the Korean government. H.Y.L., C.H.S., T.H.K.,B.J.L., and J.-S.Y. also would like to thank the Korean Basic Science Institute at Jeonju (SEM and HRTEM analysis), Daejeon (TEM analysis), and CCRF in DGIST. W.A.G. and B.V.M. thank ONR (N00014–18-1–2155) for support. W.A.G. and A.F. gratefully acknowledge support from NSF (CBET-1805022).Additional details
- Eprint ID
- 118393
- Resolver ID
- CaltechAUTHORS:20221216-550372000.4
- NRF-2019R1A2C2086770
- National Research Foundation of Korea
- NRF-2019M3A6A7023742
- National Research Foundation of Korea
- N00014-18-1-2155
- Office of Naval Research (ONR)
- CBET-1805022
- NSF
- Created
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2022-12-17Created from EPrint's datestamp field
- Updated
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2022-12-17Created from EPrint's last_modified field
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1550