bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Carbon Supports on Performance and Durability of Hydrogen Fuel Cells
Authors: Atwa Marwa , Prinz Fritz 
Published: December 2024

The global demand for clean and sustainable energy sources continues to rise, with hydrogen emerging as a key player in the energy landscape. Polymer exchange membrane fuel cells (PEMFCs) are positioned as a promising solution, converting hydrogen's chemical energy into electricity with zero emissions, which is particularly suitable for various industrial applications, including automotive.
While PEMFCs fueled by hydrogen offer superior efficiency over internal combustion engines, there's a pressing need for significant advancements in durability while maintaining high efficiency and performance, especially for light-duty vehicles. Furthermore, meeting the demands of heavy-duty applications necessitates substantial lifetime improvements (aiming for 4-5 times the current durability) alongside high efficiency.
In this presentation, we delve into the nanoengineering progress of developing highly durable and efficient cathodes for PEMFCs. Our approach leverages mesoporous carbons as supports and platinum as the electrocatalyst. Through extensive research, we've identified novel cathodes capable of achieving exceptional catalytic activity, performance, durability, and resistance to carbon corrosion—a unique combination rarely found in a single material.
Our study involved exploring a range of mesoporous carbon supports with varying porosity and graphitization degrees within a single-cell PEMFC device to identify the key characteristics conducive to robust cathode performance. By screening these supports, we've uncovered insights crucial for designing PEMFC cathodes resilient to platinum dissolution and performance losses even after undergoing several thousand accelerated durability tests while also exhibiting inherent corrosion resistance.
Robust Fuel Cell Electrodes: Pt Thin Film Catalysts for Anode Reversal Tolerance
Authors: Liyanage Wipula Priya Rasika , Ince Alper Can , Komini Babu Siddharth , Borup Rod L. , Spendelow Jacob S. 
Published: December 2024

In recent years, polymer electrolyte membrane fuel cells (PEMFCs) have garnered significant attention due to their remarkable attributes including high power density, energy efficiency, and zero-emission characteristics. This surge in interest has primarily been driven by the potential of PEMFC-powered fuel cell electric vehicles (FCEVs) to substantially reduce carbon dioxide emissions in the transportation sector, thereby propelling the advancement of the hydrogen economy on a global scale. However, the widespread commercialization of FCEVs hinges upon addressing key challenges surrounding the durability and resilience of fuel cell systems.
One critical issue that has emerged is the phenomenon of hydrogen starvation in the anode, particularly during start-up/shutdown or cold start scenarios, which can lead to rapid and severe degradation of PEMFC performance and durability through cell reversal. This degradation manifests quickly, often within minutes, resulting in abrupt cell failure. Extensive prior research has been devoted to unraveling the mechanisms underlying degradation induced by hydrogen starvation and cell reversal in PEMFCs, with the goal of identifying effective mitigation strategies to minimize damage to membrane electrode assembly (MEA) components.
In this study, we introduce an innovative materials approach aimed at mitigating cell damage by employing a thin film Pt anode catalyst supported on Nafion nanowires in a co-axial configuration, referred to as coaxial nanowire electrode (CANE). Leveraging the high roughness of Nafion nanowires, CANE eliminates the need for conventional carbon support and exhibits exceptional tolerance to reversal-induced stress. We present a comprehensive evaluation of CANE as a reversal-tolerant anode, comparing its performance to that of conventional supported catalysts (Pt/C). Furthermore, we explore the potential for further enhancing durability by integrating iridium with the CANE anode. Finally, we will delve into our efforts to evaluate the feasibility of implementing this concept in structures that can be manufactured at scale. This research contributes to the ongoing efforts to enhance the robustness and longevity of PEMFC systems, thereby advancing the prospects of FCEVs as a sustainable and viable solution for future transportation needs.
Acknowledgement
This research was supported by the Hydrogen and Fuel Cell Technologies Office (HFTO), Office of Energy Efficiency and Renewable Energy, US Department of Energy (DOE) through the Million Mile Fuel Cell Truck (M2FCT) consortia, technology managers G. Kleen and D. Papageorgopoulos. Authors would also like to acknowledge support for this work from the Laboratory Directed Research and Development (LDRD) program at Los Alamos National Laboratory (LANL) (2020200DR).
Benchmarking Electrocatalyst Stability Tests Using Lab-Scale Alkaline Water Electrolyzers
Authors: Marquez Raul A. , Espinosa Michael , Kalokowski Emma , Son Yoon Jun , Kawashima Kenta , Le Thuy Vy , Chukwuneke Chikaodili E. , Mullins C Buddie 
Published: December 2024

Green hydrogen from low-temperature water electrolysis has received significant attention, with a projected thousand-fold global capacity expansion by 2030. Electrocatalyst research is crucial for advancing water electrolysis. However, despite a surge in publications showing novel electrocatalytic materials, few studies have scaled these to more realistic setups. This gap primarily stems from the inadequacy of testing environments and operating conditions in academic research. The prevalent use of three-electrode cell configurations fails to mimic practical electrolyzer conditions accurately. Therefore, implementing stability tests in realistic device configurations is essential to assess compounded instability.
Our group has developed and optimized a lab-scale electrochemical flow cell for alkaline water electrolysis (AWE), refined over four years of dedicated research (Figure 1a). This work outlines the operation of this device in a laboratory environment, focusing on accelerating the evaluation of electrocatalytic materials and their durability. We examined the performance of this electrolyzer under industrially relevant conditions, including varying temperatures (Figure 1b). We examined the stability of three standard electrocatalytic materials to demonstrate the electrolyzer performance under fluctuating current conditions, including a benchmark NiFe anode (Figure 1c) and a nickel nitride (Ni3N) precatalyst (Figure 1d). We propose a standardized protocol for assessing electrocatalysts under fluctuating and reverse currents, contributing to the understanding of catalyst deactivation. This initiative marks a significant advancement in AWE electrocatalysis research. We aim to establish a practical and straightforward protocol for evaluating and validating electrocatalysts in AWE, fostering accurate performance comparisons.

Figure 1
Investigating Activity and Stability of Mixed-Metal Oxides (M-NiO) for Anion Exchange Membrane Electrolysis
Authors: Ha Mai-Anh , Hansen Mitchell , Mercer Emily , Norman Andrew , Miller-Link Elisa , Volk Emily K. , González Héctor , Alia Shaun M 
Published: December 2024

Recent experimental studies suggest mixed oxides of Ni, Co, and Fe operated in basic media may be the strongest alternative to iridium.1, 2 However, the efficiency of these catalysts is strongly synthesis-dependent and there is no established understanding of the role of the different metals in operation with ionomers. Notably, Trotochaud, et al. observed catalyst efficiency in the order Ni0.9Fe0.1Ox > NiOx > NiyCo1-y, whereas Morales-Guio, et. al. ranked FeNiOx, CoFeNiOx > CoNiOx > NiOx.1, 2 Anderson et al. found in their RDE studies of commercial catalysts that NiFe2O4outperformed NiO, Co3O4 by 7 times kinetically. In low concentrations, these mixed-oxide materials may behave more closely to doped-catalysts, where dopants can increase activity, change selectivity, and even improve resistance to poisoning of active sites.3-6 Understanding how and why these catalysts work, and do not work, is critical to enabling these materials to achieve the Hydrogen Shot goal of $1/kg H2 in 1 decade. For our theoretical model, we limited our mixed material model to a single dopant to fully examine the geometric and electronic effects of a nearby transition metal e.g., Fe and Co dopants. Plane-wave density functional theory calculations elucidated the dopant-effects on both activity (the oxygen evolution reaction) and stability in anion exchange membrane electrolysis in the presence of experimentally-relevant ionomers (Georgia Tech, Nafion, Versogen, and Sustainion).
(1) Trotochaud, L.; Ranney, J. K.; Williams, K. N.; Boettcher, S. W. Solution-cast metal oxide thin film electrocatalysts for oxygen evolution. Journal of the American Chemical Society
2012, 134 (41), 17253-17261.
(2) Morales-Guio, C. G.; Liardet, L.; Hu, X. Oxidatively electrodeposited thin-film transition metal (oxy) hydroxides as oxygen evolution catalysts. Journal of the American Chemical Society
2016, 138 (28), 8946-8957.
(3) Ha, M.-A.; Dadras, J.; Alexandrova, A. Rutile-deposited Pt–Pd clusters: A hypothesis regarding the stability at 50/50 ratio. ACS Cat.
2014, 4(10), 3570-3580.
(4) Baxter, E. T.; Ha, M.-A.; Cass, A. C.; Alexandrova, A. N.; Anderson, S. L. Ethylene Dehydrogenation on Pt4, 7, 8 Clusters on Al2O3: Strong Cluster Size Dependence Linked to Preferred Catalyst Morphologies. ACS Cat.
2017, 7 (5), 3322-3335.
(5) Ha, M.-A.; Baxter, E. T.; Cass, A. C.; Anderson, S. L.; Alexandrova, A. N. Boron switch for selectivity of catalytic dehydrogenation on size-selected Pt clusters on Al2O3. Journal of the American Chemical Society
2017, 139 (33), 11568-11575.
(6) Halder, A.; Ha, M.-A.; Zhai, H.; Yang, B.; Pellin, M. J.; Seifert, S.; Alexandrova, A. N.; Vajda, S. Oxidative Dehydrogenation of Cyclohexane by Cu vs Pd Clusters: Selectivity Control by Specific Cluster Dynamics. ChemCatChem
2020, 12 (5), 1307-1315. DOI: 10.1002/cctc.201901795.

Figure 1
Mechanical Alloying of Nickel-Based Catalysts for Alkaline Water Electrolysis
Authors: Phan Thu Pham Anh , Kraglund Mikkel Rykær , Lakhotiya Harish , Jensen Jens Oluf 
Published: December 2024

We have explored the catalytic properties of various Raney nickel alloys for alkaline water electrolysis (AWE), addressing the technology's challenge of low current-density operation. Different alloy compositions were successfully synthesized by high-energy ball milling under optimized conditions, resulting in a high yield (>95%) and ability to tune particle sizes, ranging from micron to submicron, within a short synthesis duration. Nickel-aluminum alloys, as precursors for Raney Ni, were synthesized. Additionally, the incorporation of third metal elements such as molybdenum (Mo), chromium (Cr), vanadium (V), was investigated, indicating the flexibility and efficiency of the synthesis method.
The crystallinity and phase composition of the alloys were analyzed by X-ray powder diffraction (XRD) as shown in Figure 1A. Thermal effects on alloy phase changes were investigated through in-situ XRD analysis. The finding revealed significant alterations in crystallinity and phase composition of Ni-Al alloy at temperatures exceeding 700 oC, consequently impacting catalytic performance.
Subsequently, the synthesized catalyst powders were applied onto electrode substrates using an airbrushing technique (Figure 1B). Following an activation procedure, the catalysts were evaluated through half-cell electrochemical measurements, with selected samples tested for stability in a flow cell setup. Catalytic performance of electrodes prepared with the synthesized Raney Ni catalyst exhibited substantial enhancement towards the hydrogen evolution reaction (HER) compared to bare Ni substrate. With catalyst loading of 3 mg/cm2, a notably low overpotential of 59 mV was achieved at current density of 50 mA/cm2 in 1M KOH.
The research is funded by Stiesdal Hydrogen A/S.

Figure 1
Iridium Oxide and Niobium-Doped Iridium Oxide Anodes for PEM Water Electrolysis: Towards Sustainable Hydrogen Production with Superior Performance
Authors: Lenhart Brian , Nguyen Van , Wagner Lindsay , Mckinney Samuel , Ostraat Michele 
Published: December 2024

The global push towards cleaner energy sources has heightened the demand for high-performing, durable proton exchange membrane water electrolyzer (PEMWE) electrocatalysts. Green hydrogen, generated through water electrolysis powered by renewable energy, stands as a prominent solution in this endeavor to transition away from fossil fuels. Among various electrolyzer technologies, PEMWE systems currently offer the most competitive pathway for green hydrogen production. These systems typically employ a platinum on carbon supported (Pt/C) cathodic electrocatalyst for the hydrogen evolution reaction (HER) and an iridium oxide (IrOx) anodic electrocatalyst for the oxygen evolution reaction (OER). Efforts to enhance PEMWE performance primarily focus on improving the kinetics of the OER process, which accounts for the majority of activation overpotential during operation. To address cost concerns associated with IrOx, researchers are exploring alternative formulations, including doping with materials like niobium (Nb), aiming for comparable performance at reduced Ir loading [1], [2], [3]. It is argued that higher surface area and lower crystalline IrOx catalysts lead to lower activation overpotentials and enhanced durability, respectively. In this study, we investigate the performance of high-surface-area IrOx electrocatalysts (>200 m2/g) and Nb-doped IrOx variants, comparing them with commercially available benchmarks. Through rigorous examination utilizing Rotating Disk Electrode (RDE), Gas Diffusion Electrode (GDE) half-cell, and Membrane Electrode Assemblies (MEAs), we report on the performance and stability of our in-house prepared materials. Preliminary results examining various loadings of IrOx suggest that lower loadings lead to durable and active electrocatalyst layers. Our findings underscore the potential of Nb-doped IrOx as a cost-effective alternative for PEMWE electrocatalysts, offering promising advancements in the pursuit of efficient and sustainable hydrogen production.
References:
[1] C. Baik, S. W. Lee, and C. Pak, “Glycine-induced ultrahigh-surface-area IrO2@IrOx catalyst with balanced activity and stability for efficient water splitting,” Electrochim Acta, vol. 390, Sep. 2021, doi: 10.1016/j.electacta.2021.138885.
[2] K. Zhang et al., “Status and perspectives of key materials for PEM electrolyzer,” Nano Research Energy, vol. 1, no. 3. Tsinghua University Press, Dec. 01, 2022. doi: 10.26599/NRE.2022.9120032.
[3] X. Duan et al., “Boosting the efficiency of IrOx nanoparticles with micron-flower Nb4N5 support for oxygen evolution reaction in polymer electrolyte membrane water electrolyzer,” Electrochim Acta, vol. 470, Dec. 2023, doi: 10.1016/j.electacta.2023.143271.
The Role of Porous Transport Layer in Enabling Low Anode Catalyst Loadings
Authors: Wrubel Jacob A , Parimuha Makenzie , Young James L. , Bender Guido 
Published: December 2024

Hydrogen (H2) is a focal point of the U.S. Department of Energy’s (DOE) plan for a future energy economy that is secure, resilient, and environmentally friendly [1]. And proton exchange membrane water electrolysis (PEMWE) is a promising technology for renewable H2 production. Yet, state-of-the-art PEMWEs use significant amounts of expensive platinum group metals (PGMs), namely, Pt and Ir, which leads to large capital expenses (CapEx). Techno-economic analysis has shown that CapEx is just as, if not more, important as operating expenses (OpEx) for enabling $1/kgH2.
In recent years, the price of Ir has significantly increased, even compared to Pt. Reducing the Ir loading in a PEMWE cell or stack is a straightforward way to reduce CapEx. However, anode catalyst layers (ACLs) with reduced Ir loadings tend to suffer from poor electrical in-plane conductivity and low utilization, leading to significantly higher overpotentials. Supported catalyst materials, i.e., Ir decorated onto a conductive substrate material, could help address these drawbacks, but the catalyst support material must also be stable at the elevated potentials seen by the anode. To date there is no suitable support material that offers both stability and good performance. Therefore, strategies to improve performance using unsupported Ir are of great value.
In this work, we studied 6 different commercial porous transport layer (PTL) materials to observe their effect on cell performance as the anode Ir content was reduced. The PTL is responsible for conducting electrons from the ACL. The morphology of the PTL and the structure of the ~2D interface it creates with the ACL can strongly affect overpotentials associated with in-plane electronic resistance and impact catalyst utilization. All PTLs studied were made from pure Ti. They included both fibrous and sintered particle archetypes. Beginning of life and 1000 h durability results from studies with both 0.1 mgIr/cm2 and 0.4 mgIr/cm2 loadings will be discussed in the presentation. For example, as seen in Figure 1, we found that the PTL greatly influences cell performance at ACL loadings of 0.1 mgIr/cm2, though the effect was less pronounced at 0.4 mgIr/cm2. Changes in both ohmic and kinetic overpotentials were observed.

References:

[1] Pivovar B, Rustagi N, Satyapal S. Hydrogen at Scale (H2@Scale): Key to a Clean, Economic, and Sustainable Energy System. Electrochem. Soc. Interface 2018; 27:47–52.

Figure 1
The Electrochemical Kinetics of the H-Upd and O-Upd on Polycrystalline Platinum
Authors: Brandes Benedikt Axel , Moretti Enzo 
Published: December 2024

Underpotential depositited hydrogen on different platinum surfaces has been studied for over a century, yet we know very little about its nature. This is due to a combination of experimental limitations of surface characterisation, attributed to most techniques being virtually blind to adsorbed hydrogen atoms through the present electrolyte layer.
In this work I present a thourough mathematical derivation of the kinetics of the H-upd, the O-upd, and mass transport phenomena from the Butler-Volmer model. Through a new measurement approach I am then able to estimate the local pH on the Pt surface allowing me to determine the rate constant of the process behind the H-upd. An extensive survey in a wide range of electrolytes reveals a astonishing consistency of the rate constant but also a surprsing dependency of the the presence of molecular hydrogen. I wish to start a debate if the extracted kinetic parameters truly represent the rate constant of the H-upd or are mere artefact of the employed measurement method.
Eventually I will illuminate the debate on the origin of the observed CV patterns, notably the role of cations and anions, and provide insights into the role of the H-upd in respect to the HOR/HER and how its study can advance the development of new electrocatalysts.

Figure 1
Investigation on the Interaction of Catalyst and Ionomer in AEM Electrolysis
Authors: Chan Ai-Lin , Clauser Arielle L , Kreider Melissa E , Volk Emily K. , Sugar Josh D , Alia Shaun M 
Published: December 2024

In low temperature electrolysis, anion exchange membrane (AEM) systems combine the advantages of alkaline and proton exchange membrane (PEM) electrolysis in generating high purity hydrogen and reducing material costs from catalysts and component coatings [1]. Recent studies in AEM electrolysis have focused on improving cell performance, minimizing catalyst dissolution and mitigating ionomer/membrane degradation with different operating conditions. Ionomers play a critical role in the electrode because they provide ion conductivity, enhance mechanical support, and create preferred morphologies for electrolyte and produced gas to move [2, 3]. Optimizing catalyst-ionomer interactions by varying ionomer content, chemistries, and forms can accelerate the development of AEM electrolysis in terms of performance enhancement, cost and lifetime.
In this work, different forms of ionomer (powdered and dispersed) with two polymer backbones were evaluated in AEM electrolysis cell testing. Ni- and Co-based oxides and IrO2 were applied as anode catalysts. In Figure 1, the anodes with powdered ionomer outperform the dispersed samples. With Co3O4 catalyst, the overpotential can be improved by 0.9 V at 1 A/cm2 (iR-free voltage of Co3O4 with powdered ionomer: 1.68 V at 1 A/cm2). By electrochemical diagnostic and modeling methods, the improved performance with powdered ionomer is attributed to better reaction kinetic from more active area between catalysts and ionomers, less ohmic overpotentials due to better contact between the electrode and the transport layer and preferred transport properties with higher porosity created by powdered ionomer. Scanning electron microscopy data verifies that the anodes with powdered ionomer provide more homogeneous distribution of catalysts and ionomer in the electrode, while dispersed samples have the issues of agglomerates and uneven coverage of catalysts, which could worsen the catalyst utilization and trigger mass transport issues.
[1] Ayers, Katherine, et al. "Perspectives on low-temperature electrolysis and potential for renewable hydrogen at scale." Annual review of chemical and biomolecular engineering 10 (2019): 219-239.
[2] Lee, Sol A., et al. "Anion exchange membrane water electrolysis for sustainable large‐scale hydrogen production." Carbon Neutralization 1.1 (2022): 26-48.
[3] Favero, Silvia, Ifan EL Stephens, and Maria‐Magdalena Titirci. "Anion Exchange Ionomers: Design Considerations and Recent Advances‐An Electrochemical Perspective." Advanced Materials 36.8 (2024): 2308238.

Figure 1