Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study

Kabir, Sadia; Myers, Deborah J.; Kariuki, Nancy; Park, Jaehyung; Wang, Guanxiong; Baker, Andrew; Macauley, Natalia; Mukundan, Rangachary; More, Karren L.; Neyerlin, Kenneth C.

doi:10.1021/acsami.9b11365

Title: Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study

Full Record
Other Related Research

Abstract

To increase the commercialization of fuel cell electric vehicles, it is imperative to improve the activity and performance of electrocatalysts through combined efforts focused on material characterization and device-level integration. Obtaining fundamental insights into the ongoing structural and compositional changes of electrocatalysts is crucial for not only transitioning an electrode from its as-prepared to functional state, also known as 'conditioning', but also for establishing intrinsic electrochemical performances. Here, we investigated several oxygen reduction reaction (ORR) electrocatalysts via in situ and ex situ characterization techniques to provide fundamental insights into the interfacial phenomena that enable peak ORR mass activity and high current density performance. A mechanistic understanding of a fuel cell conditioning procedure is described, which encompasses voltage cycling and subsequent voltage recovery (VR) steps at low potential. In particular, ex situ membrane electrode assembly characterization using transmission electron microscopy and ultra-small angle X-ray scattering were performed to determine changes in carbon and Pt particle size and morphology, while in situ electrochemical diagnostics were performed either during or after specific points in the testing protocol to determine the electrochemical and interfacial changes occurring on the catalyst surface responsible for oxygen transport resistances through ionomer films. The results demonstrate that the voltagemore »« less

Authors:

^[1]; Myers, Deborah J. ^[2]; Kariuki, Nancy ^[2]; Park, Jaehyung ^[2]; Wang, Guanxiong ^[1]; Baker, Andrew ^[3]; Macauley, Natalia ^[3]; Mukundan, Rangachary ^[3]; More, Karren L. ^[4];

^[1]

National Renewable Energy Lab. (NREL), Golden, CO (United States)
Argonne National Lab. (ANL), Argonne, IL (United States)
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: 2019-11-06

Research Org.:: National Renewable Energy Lab. (NREL), Golden, CO (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE). Fuel Cell Technologies Program; USDOE Office of Energy Efficiency and Renewable Energy (EERE). Fuel Cell Technologies Program (EE-3F)

OSTI Identifier:: 1578259

Alternate Identifier(s):: OSTI ID: 1606548; OSTI ID: 1608686; OSTI ID: 1761699

Report Number(s):: NREL-JA-5900-74853; LA-UR-19-31350
Journal ID: ISSN 1944-8244

Grant/Contract Number:: AC36-08GO28308; 89233218CNA000001; AC05-00OR22725; AC02-06CH11357

Resource Type:: Accepted Manuscript

Journal Name:: ACS Applied Materials and Interfaces

Additional Journal Information:: Journal Volume: 11; Journal Issue: 48; Journal ID: ISSN 1944-8244

Publisher:: American Chemical Society (ACS)

Country of Publication:: United States

Language:: English

Subject:: 30 DIRECT ENERGY CONVERSION; fuel cell; electrocatalyst; conditioning; electrochemical diagnostics; kinetics; oxygen transport resistances; energy sciences

Citation Formats


                    Kabir, Sadia, Myers, Deborah J., Kariuki, Nancy, Park, Jaehyung, Wang, Guanxiong, Baker, Andrew, Macauley, Natalia, Mukundan, Rangachary, More, Karren L., and Neyerlin, Kenneth C. Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study.  United States: N. p., 2019. 
Web.  doi:10.1021/acsami.9b11365.

Copy to clipboard


                    Kabir, Sadia, Myers, Deborah J., Kariuki, Nancy, Park, Jaehyung, Wang, Guanxiong, Baker, Andrew, Macauley, Natalia, Mukundan, Rangachary, More, Karren L., & Neyerlin, Kenneth C. Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study.  United States.  https://doi.org/10.1021/acsami.9b11365

Copy to clipboard


                    Kabir, Sadia, Myers, Deborah J., Kariuki, Nancy, Park, Jaehyung, Wang, Guanxiong, Baker, Andrew, Macauley, Natalia, Mukundan, Rangachary, More, Karren L., and Neyerlin, Kenneth C. Wed .  
"Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study".  United States.  https://doi.org/10.1021/acsami.9b11365.  https://www.osti.gov/servlets/purl/1578259.

Copy to clipboard


                    
@article{osti_1578259,

  title        = {Elucidating the Dynamic Nature of Fuel Cell Electrodes as a Function of Conditioning: An ex Situ Material Characterization and in Situ Electrochemical Diagnostic Study},

  author       = {Kabir, Sadia and Myers, Deborah J. and Kariuki, Nancy and Park, Jaehyung and Wang, Guanxiong and Baker, Andrew and Macauley, Natalia and Mukundan, Rangachary and More, Karren L. and Neyerlin, Kenneth C.},

  abstractNote = {To increase the commercialization of fuel cell electric vehicles, it is imperative to improve the activity and performance of electrocatalysts through combined efforts focused on material characterization and device-level integration. Obtaining fundamental insights into the ongoing structural and compositional changes of electrocatalysts is crucial for not only transitioning an electrode from its as-prepared to functional state, also known as 'conditioning', but also for establishing intrinsic electrochemical performances. Here, we investigated several oxygen reduction reaction (ORR) electrocatalysts via in situ and ex situ characterization techniques to provide fundamental insights into the interfacial phenomena that enable peak ORR mass activity and high current density performance. A mechanistic understanding of a fuel cell conditioning procedure is described, which encompasses voltage cycling and subsequent voltage recovery (VR) steps at low potential. In particular, ex situ membrane electrode assembly characterization using transmission electron microscopy and ultra-small angle X-ray scattering were performed to determine changes in carbon and Pt particle size and morphology, while in situ electrochemical diagnostics were performed either during or after specific points in the testing protocol to determine the electrochemical and interfacial changes occurring on the catalyst surface responsible for oxygen transport resistances through ionomer films. The results demonstrate that the voltage cycling (break-in) step aids in the removal of sulfate and fluoride and concomitantly reduces non-Fickian oxygen transport resistances, especially for catalysts where Pt is located within the pores of the carbon support. Subsequent low voltage holds at low temperature and oversaturated conditions, i.e., VR cycles, serve to improve mass activities by a factor of two to three, through a combined removal of contaminants, surface-blocking species (e.g., oxides), and rearrangement of the catalyst atomic structure (e.g., Pt-Pt and Pt-Co coordination).},

  doi          = {10.1021/acsami.9b11365},

  journal      = {ACS Applied Materials and Interfaces},

  number       = 48,

  volume       = 11,

  place        = {United States},

  year         = {2019},

  month        = {11}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1021/acsami.9b11365

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 11 works

Citation information provided by
Web of Science

Save / Share:

Export Metadata

Save to My Library

Similar Records in DOE PAGES and OSTI.GOV collections:

Electrocatalysis in Alkaline Media and Alkaline Membrane-Based Energy Technologies

Journal Article Yang, Yao ; Peltier, Cheyenne R. ; Zeng, Rui ; ... - Chemical Reviews

Hydrogen energy-based electrochemical energy conversion technologies offer the promise of enabling a transition of the global energy landscape from fossil fuels to renewable energy. Here, we present a comprehensive review of the fundamentals of electrocatalysis in alkaline media and applications in alkaline-based energy technologies, particularly alkaline fuel cells and water electrolyzers. Anion exchange (alkaline) membrane fuel cells (AEMFCs) enable the use of nonprecious electrocatalysts for the sluggish oxygen reduction reaction (ORR), relative to proton exchange membrane fuel cells (PEMFCs), which require Pt-based electrocatalysts. However, the hydrogen oxidation reaction (HOR) kinetics is significantly slower in alkaline media than in acidic media.more »« less
https://doi.org/10.1021/acs.chemrev.1c00331
Use of in Situ Synchrotron Techniques to Probe the Oxidized Surface of Molybdenum Nitride Oxygen Reduction Electrocatalysis

Conference Kreider, Melissa ; Stevens, Michaela B. ; Gibbons, Brenna ; ...

The development of active and stable earth-abundant catalysts for the oxygen reduction reaction (ORR) is needed for widespread, economic development of fuel cell technologies. Designing and optimizing these non-platinum group metals is challenging, however, because they are susceptible to composition and structure changes, including dissolution, oxidation, and corrosion, both in air and under reaction conditions. To identify the active surface, and thus understand the properties that affect activity, the catalyst surface must be characterized in situ. Herein, we utilize a grazing incidence electrochemical cell to investigate in situ composition and morphology changes of a molybdenum nitride (Mo-N) thin film catalystmore »« less
Full Text Available
Identifying and Tuning the In Situ Oxygen-Rich Surface of Molybdenum Nitride Electrocatalysts for Oxygen Reduction

Journal Article Stevens, Michaela Burke ; Kreider, Melissa E. ; Patel, Anjli M. ; ... - ACS Applied Energy Materials

Rigorous in situ studies of electrocatalysts are required to enable the design of higher performing materials. Nonplatinum group metals for oxygen reduction reaction (ORR) catalysis containing light elements such as O, N, and C are known to be susceptible to both ex situ and in situ oxidation, leading to challenges associated with ex situ characterization methods. We have previously shown that the bulk O content plays an important role in the activity and selectivity of Mo–N catalysts, but further understanding of the role of composition and morphological changes at the surface is needed. Here, we report the measurement of inmore »« less
https://doi.org/10.1021/acsaem.0c02423

Full Text Available
Impact of Catalyst Ink Dispersing Methodology on Fuel Cell Performance Using in-Situ X-ray Scattering

Journal Article Wang, Min ; Park, Jae Hyung ; Kabir, Sadia ; ... - ACS Applied Energy Materials

This work presents a study of the effects of ultrasonic dispersing methodology and time on catalyst agglomerate size in polymer electrolyte membrane fuel cell catalyst ink dispersions. Cathode catalyst inks were prepared and characterized to elucidate the influences of ultrasonic dispersing method and time on catalyst ink particle size and CCL electrochemical properties. In situ ultra-small-, small-, and wide-angle X-ray scattering analyses were used to study the impact of ultrasonication time and methodology on changes in the agglomerate, aggregate, and particle size and distribution during the dispersing process. Ex-situ transmission electron microscopy was also used to investigate the particle sizemore »« less
Cited by 8
https://doi.org/10.1021/acsaem.9b01037

Full Text Available
Atomic Structure of Pt₃Ni Nanoframe Electrocatalysts by in Situ X-ray Absorption Spectroscopy.

Journal Article Becknell, Nigel ; Kang, Yijin ; Chen, Chen ; ... - Journal of the American Chemical Society

Understanding the atomic structure of a catalyst is crucial to exposing the source of its performance characteristics. It is highly unlikely that a catalyst remains the same under reaction conditions when compared to as-synthesized. Hence, the ideal experiment to study the catalyst structure should be performed in situ. Here, we use X-ray absorption spectroscopy (XAS) as an in situ technique to study Pt₃Ni nanoframe particles which have been proven to be an excellent electrocatalyst for the oxygen reduction reaction (ORR). The surface characteristics of the nanoframes were probed through electrochemical hydrogen underpotential deposition and carbon monoxide electrooxidation, which showed thatmore »« less
Cited by 119
https://doi.org/10.1021/jacs.5b09639

Full Text Available

Similar Records