Hydrogen fuel can be produced from zero-carbon sources using the electrochemical process of water electrolysis coupled with renewable zero-carbon sources of electricity, such as wind, solar, and nuclear power. The advantage of PEFCs is their high efficiency in converting fuel to electricity with low emissions and at low operating temperatures. The fuel of choice for many PEFC power applications is hydrogen due to its high energy density per mass of fuel, high conversion efficiency and non-carbon-containing emissions. The major issues impeding the widespread implementation of hydrogen-fueled PEFC power systems are hydrogen fuel cost, hydrogen fueling infrastructure, hydrogen storage, and PEFC system cost and lifetime. The Hydrogen and Fuel Cell Materials group in CSE has active research projects to develop new materials and enable existing materials to overcome the major barriers to enable cost-competitive use of hydrogen and PEFCs in a variety of applications.
Hydrogen can play a key role in decarbonizing many sectors beyond transportation, such as residential and commercial electricity and steel and ammonia production. Hydrogen can be produced from zero-carbon sources and processes, such as electrolysis of water, using renewable or nuclear energy. To be widely adopted, however, hydrogen must be cost competitive with incumbent fuels. In 2021, the U.S. Department of Energy announced the first Energy Earth Shot aimed at addressing the main issues with production of hydrogen using electrolysis: cost. The Hydrogen Shot established the goal of reaching $1 per kilogram of hydrogen in one decade (“1,1,1”). The current projected cost of hydrogen by low-temperature water electrolysis using a polymer electrolyte electrolyzer is between 3 and 5 times higher than this target due to the cost of electricity and the capital cost of the precious metal catalysts. The Hydrogen and Fuel Cell Materials group has active research projects to develop new materials and enable existing materials to reach the Hydrogen Shot targets and to enable cost-competitive use of this promising technology in a variety of applications.
This work is primarily funded by the Hydrogen and Fuel Cell Technologies Office (HFTO) in the Department of Energy’s (DOE) Office of Energy Efficiency and Renewable Energy. The focus of HFTO has historically been on the automotive application, where cost competitiveness with the incumbent internal combustion engine requires PEFCs with low loadings of costly platinum-based electrocatalyst. Recently, HFTO’s R&D emphasis has shifted to PEFC systems for heavy duty vehicles, such as long-haul trucks. In 2020 HFTO established a consortium of five core national laboratories to address PEFC performance and durability for heavy-duty applications called the Million Mile Fuel Cell Truck consortium (M2FCT). The emphasis here is on efficiency (i.e., current density at high voltages) and durability and less on cost. In 2020, HFTO also established another national laboratory consortium to address the cost, efficiency, and lifetime issues with the production of hydrogen from low and high-temperature electrolysis: Hydrogen from the Next Generation of Electrolyzers of Water (H2NEW). This consortium aims to reduce the cost of hydrogen produced by these processes to $2/kg by 2025 toward the ultimate Hydrogen Shot goal of $1/kg by 2030.
In support of decarbonization efforts, DOE is also exploring processes to convert carbon dioxide into liquid fuels or chemicals. One such process converts captured carbon dioxide to fuels/chemicals such as methanol, ethanol, isopropanol, and acetone using direct electrochemical reduction. Along with water electrolysis to produce hydrogen, these electrochemical processes can serve as effective means to store and utilize the energy produced from intermittent, renewable sources such as solar and wind.
Our research addresses the main issues facing the widespread deployment of PEFC power systems for numerous applications: performance, durability and cost. The group’s research also addresses the use of fuel cells for transportation applications: lack of cost-effective hydrogen and suitable high-capacity hydrogen storage materials. Additionally, the group is also developing materials and supporting the development of cells for the electrochemical conversion of carbon dioxide to fuels/chemicals.
PGM Free Catalysts
A major cost contributor to PEFC power systems and low-temperature water electrolysis hydrogen production systems and one of the major sources of efficiency loss for both technologies are the platinum group metal oxygen reduction reaction and oxygen evolution reaction catalysts. To address this issue, the Hydrogen and Fuel Cell Materials group is developing platinum group metal-free (PGM-free) catalysts with the aim of maximizing the active site density, accessibility of the active sites, and the activity and durability of those sites. Among other tools, to achieve these goals, the group is utilizing high-throughput materials synthesis coupled with machine learning,1 characterization2 and equipment and methodologies development for performance evaluation.3 This research takes advantage of the capabilities within CSE’s high-throughput research laboratory. This activity is a cornerstone of the DOE’s ElectroCat consortium, which is co-led by Argonne and Los Alamos National Laboratory.
Platinum Alloy Electrocatalysts
Another of the group’s research areas focuses on developing novel platinum and platinum alloy catalysts and on achieving high performance from advanced platinum alloy electrocatalysts by tuning the electrode layer composition and structure. One such novel catalyst approach utilizes a PGM-free catalyst as a support for platinum alloy nanoparticles.4 The group also seeks to determine the performance and durability-limiting properties of platinum and platinum alloy catalysts, electrode layer precursor solutions, and electrodes utilizing a combination of in-cell diagnostics and structural analyses, ex situ time-resolved detection of catalyst degradation products, and X-ray scattering, spectroscopy, and tomography techniques at Argonne’s Advanced Photon Source.5,6 The information from these characterizations and the impact of electrode layer composition and precursor solution solvent on the performance and structure is used to inform the design of electrodes with technology-enabling performance and durability for the automotive and heavy duty vehicle applications. This work is part of the DOE Hydrogen and Fuel Cell Technologies Office’s Million Mile Fuel Cell Truck Consortium (M2FCT).
Our group is also addressing the limited durability of PEFCs by identifying the mechanisms of catalyst degradation and determining the catalyst, catalyst support properties and operating conditions that limit catalyst lifetime. This research utilizes ex situ, in situ, and operando X-ray absorption and scattering techniques at Argonne’s Advanced Photon Source, aqueous dissolution studies, modeling of platinum dissolution and de-alloying, and modeling of the effect of catalyst degradation on cell performance, in collaboration with Argonne’s Energy Systems and Infrastructure Analysis Division.7,8 This work is also part of M2FCT.
Water electrolysis to form hydrogen represents one of the critical technologies for distributed hydrogen production. Barriers to widespread implementation of this hydrogen production technology are cost and lifetime/durability. Due to the sluggish kinetics of the oxygen evolution reaction (OER), high loadings of costly iridium are needed to achieve reasonable electrolyzer efficiency and durability. The group is developing PGM-free OER catalysts to address the cost and durability issues of iridium OER catalysts. These materials are based on porous, stable transition metal composites derived from, for example, cobalt metal organic frameworks incorporated into a 3-D nano-network architecture.9
The group is also part of the DOE-HFTO “Hydrogen from the Next Generation of Electrolyzers of Water” consortium (H2NEW), which aims to lower the cost of hydrogen by improving existing designs and materials of proton exchange membrane and solid oxide water electrolyzers. The group’s roles in the consortium are to define catalyst, electrode design, and operating conditions to improve the performance and extend the lifetime of the electrolyzers. We are utilizing a combination of in situ and operando X-ray absorption spectroscopy and scattering coupled with on-line inductively-coupled plasma mass spectrometry techniques to determine the mechanisms of catalyst degradation, to link catalyst atomic structure with performance, and to define the interactions in the catalyst-ionomer ink determining electrode structure and performance.
Carbon Dioxide to Fuel
Our group, in collaboration with Northern Illinois University, is developing highly effective and selective transition metal-based catalysts for the direct electrochemical conversion of carbon dioxide to value-added, multi-carbon organic chemicals such as ethanol, acetone, and isopropanol.10, 11 In addition to supporting initiatives from DOE’s Advanced Manufacturing Office (AMO), we are also working on commercializing our CO2 reduction catalysts and electrolyzer technology with sponsorship from DOE’s Fossil Energy and Carbon Management Office (FECM). In collaboration with the National Renewable Energy Laboratory, the group is also providing critical information for the development of selective, high efficiency, high current density cells for the conversion of carbon dioxide to fuels, such as formaldehyde.12
- M. Karim, M. Ferrandon, S. Medina, E. Sture, N. Kariuki, D.J. Myers, E.F. Holby, P. Zelenay, and T. Ahmed, ACS Applied Energy Materials, doi:10.1021/acsaem.0c01466 (2020).
- Luigi Osmieri, Rajesh K. Ahluwalia, Xiaohua Wang, Hoon T. Chung, Xi Yin, A. Jeremy Kropf, Jaehyung Park, David A. Cullen, Karren L. More, Piotr Zelenay, Deborah J. Myers, and K.C. Neyerlin, Applied Catalysis B: Environmental, 257 (2019) 117929.
- Jaehyung Park and Deborah J. Myers, Journal of Power Sources, 480 (2020) 228801-228810.
- L. Chong, J. Wen, J. Kubal, F. Sen, J. Zou, J. Greeley, M. Chan, H. Barkholtz, W. Ding, D.-J. Liu, Science, 362 (2018) 1276-1281.
- Min Wang, Jae Hyung Park, Sadia Kabir, K.C. Neyerlin, Nancy N. Kariuki, Haifeng Lv, Vojislav R. Stamenkovic, Deborah J. Myers, Michael Ulsh, and Scott Mauger, ACS Applied Energy Materials, 2 (2019) 6417-6427.
- Firat C. Cetinbas, Rajesh K. Ahluwalia, Nancy N. Kariuki, Vincent De Andrade, and Deborah J. Myers, Journal of the Electrochemical Society, 167 (2020) 013508-013516.
- Deborah J. Myers, Xiaoping Wang, Matt C. Smith, and Karren L. More, Journal of the Electrochemical Society, 165(6) (2018) F3178-F3190.
- Rajesh K. Ahluwalia, Dionissios D. Papadias, Nancy N. Kariuki, Jui-Kun Peng, Xiaoping Wang, Yifen Tsai, Donald G. Graczyk, and Deborah J. Myers, Journal of the Electrochemical Society, 165(6) (2018) F3024-F3035.
- Di-Jia Liu, Gang Wu, and Hui Xu, “PGM-free OER Catalysts for PEM Electrolyzer,” 2020 DOE Hydrogen and Fuel Cells Program Annual Merit Review and Peer Evaluation Meeting, https://www.hydrogen.energy.gov/pdfs/review20/p157_liu_2020_p.pdf.
- Haiping Xu, Dominic Rebollar, Haiying He, Lina Chong, Yuzi Liu, Cong Liu, Cheng-Jun Sun, Tao Li, John V. Muntean, Randall E. Winans, Di-Jia Liu, and Tao Xu, Nature Energy, 5 (2020) 623-632.
- Di-Jia Liu, Joule (2022) in press.
- Yingying Chen, Ashlee Vise, Ellis Klein, Firat C. Cetinbas, Deborah J. Myers, Wilson A. Smith, Todd G. Deutsch, and K.C. Neyerlin, ACS Energy Letters, 5 (2020) 1825-1833.