Title: Atomically dispersed single iron sites for promoting Pt and Pt₃Co fuel cell catalysts: performance and durability improvements

Abstract

Significantly reducing platinum group metal (PGM) loading while improving catalytic performance and durability is critical to accelerating proton-exchange membrane fuel cells (PEMFCs) for transportation. In this study, we report an effective strategy to boost PGM catalysts through integrating PGM-free atomically-dispersed single metal active sites in the carbon support toward the cathode oxygen reduction reaction (ORR). We achieved uniform and fine Pt nanoparticle (NP) (~2 nm) dispersion on an already highly ORR-active FeN₄ site-rich carbon (FeN₄–C). Furthermore, we developed an effective approach to preparing a well-dispersed and highly ordered L1₂ Pt₃Co intermetallic nanoparticle catalyst on the FeN₄–C support. DFT calculations predicted a synergistic interaction between Pt clusters and surrounding FeN₄ sites through weakening O₂ adsorption by 0.15 eV on Pt sites and reducing activation energy to break O–O bonds, thereby enhancing the intrinsic activity of Pt. Experimentally, we verified the synergistic effect between Pt or Pt₃Co NPs and FeN₄ sites, leading to significantly enhanced ORR activity and stability. Especially in a membrane electrode assembly (MEA) with a low cathode Pt loading (0.1 mg_Pt cm^–2), the Pt/FeN₄–C catalyst achieved a mass activity of 0.451 A mg_Pt^–1 and retained 80% of the initial values after 30 000 voltage cycles (0.60 to 0.95 V),more » exceeding DOE 2020 targets. Furthermore, the Pt₃Co/FeN₄ catalyst achieved significantly enhanced performance and durability concerning initial mass activity (0.72 A mg_Pt^–1), power density (824 mW cm^–2 at 0.67 V), and stability (23 mV loss at 1.0 A cm^–2). The approach to exploring the synergy between PGM and PGM-free Fe–N–C catalysts provides a new direction to design advanced catalysts for hydrogen fuel cells and various electrocatalysis processes.« less

Authors:

Qiao, Zhi ^[1]; Wang, Chenyu ^[2]; Li, Chenzhao ^[3]; Zeng, Yachao ^[1]; Hwang, Sooyeon  ^[4];

• Search DOE PAGES for author "Hwang, Sooyeon"
• Search DOE PAGES for ORCID "0000-0001-5606-6728"

Li, Boyang ^[5]; Karakalos, Stavros  ^[6];

• Search DOE PAGES for author "Karakalos, Stavros"
• Search DOE PAGES for ORCID "0000-0002-3428-5433"

Park, Jaehyung ^[7]; Kropf, A. Jeremy  ^[7];

• Search DOE PAGES for author "Kropf, A. Jeremy"
• Search DOE PAGES for ORCID "0000-0002-3329-4493"

Wegener, Evan C. ^[7]; Gong, Qing ^[3]; Xu, Hui ^[8]; Wang, Guofeng  ^[5];

• Search DOE PAGES for author "Wang, Guofeng"
• Search DOE PAGES for ORCID "0000-0001-8249-4101"

Myers, Deborah J. ^[7]; Xie, Jian ^[3]; Spendelow, Jacob S. ^[2]; Wu, Gang  ^[1]

• Search DOE PAGES for author "Wu, Gang"
• Search DOE PAGES for ORCID "0000-0003-0885-6172"

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+ Show Author Affiliations

1. Univ. at Buffalo, NY (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
3. Indiana Univ.-Purdue Univ. Indianapolis (IUPUI), Indianapolis, IN (United States)
4. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
5. Univ. of Pittsburgh, PA (United States)
6. Univ. of South Carolina, Columbia, SC (United States)
7. Argonne National Lab. (ANL), Argonne, IL (United States). Chemical Sciences and Engineering Division
8. Giner, Inc., Newton, MA (United States)

Publication Date:

Sat Jun 26 00:00:00 EDT 2021

Research Org.:

Brookhaven National Laboratory (BNL), Upton, NY (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Giner, Inc., Newton, MA (United States); Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Hydrogen Fuel Cell Technologies Office (HFTO); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)

OSTI Identifier:

1813955

Alternate Identifier(s):

OSTI ID: 1811577; OSTI ID: 1826171; OSTI ID: 1875998; OSTI ID: 1996174; OSTI ID: 2208791

Report Number(s):

BNL-222007-2021-JAAM; LA-UR-21-23020; LA-UR-22-25271
Journal ID: ISSN 1754-5692

Grant/Contract Number:  

SC0012704; AC02-06CH11357; 89233218CNA000001; 20200200DR; SC0021671

Resource Type:

Accepted Manuscript

Journal Name:

Energy & Environmental Science

Additional Journal Information:

Journal Volume: 14; Journal Issue: 9; Journal ID: ISSN 1754-5692

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; Energy Sciences; Material Science