bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elucidating 3D Water Distributions in PEM Water Electrolyzers Via Neutron Imaging
Authors: Seip Tess , Lee Jongmin , Zhu Lijun , Ranieri Salvatore , Chadwick Eric Alexander , Krause Kevin , Helfen Lukas , Auvity Bruno , Chevalier Stéphane , Bazylak Aimy 
Published: December 2024

A key challenge in polymer electrolyte membrane (PEM) water electrolysis stems from product oxygen bubble accumulation in the titanium (Ti) porous transport layer (PTL), which limits hydrogen production at high current densities. To design the next generation of PTLs with efficient porous structures that enhance bubble removal, obtaining three-dimensional (3D) water and gas distributions in an operating electrolyzer is critical. Previous works have demonstrated that neutron [1,2] and X-ray [3] imaging techniques can be used to quantify gas and water content, but capturing these phenomena with 3D imaging remains a challenge due to low transmission through metallic cell hardware, limitations in spatial and temporal resolutions, and low contrast between reactant water and product gas bubbles.
In this work, we used the high flux neutron beam at the NeXT instrument of the Institut Laue-Langevin to perform operando radiography during electrolysis and to acquire tomography scans of the steady-state water and gas distributions. We designed a custom PEM electrolysis cell with a Ti PTL and serpentine flow field design for neutron radiography and tomography to reveal the water distribution and its evolution in the PTL. To correlate electrochemical losses to reactant distributions, polarization curves and EIS measurements were acquired. Operando radiography was employed to reveal changes in water distributions over time with increasing current density. Additionally, to elucidate the steady-state water and gas distributions at a variety of current densities, neutron tomography was utilized. Within our analysis, we reveal the impact of water and bubble distributions through the PTL on activation, ohmic, and mass transport overpotentials, particularly at the PTL and catalyst layer interface. The insights provided will aid in identifying performance degradation mechanisms and desirable reactant distributions for the next generation of PTL design.

References

J. K. Lee et al., Energy Convers Manag, 226, 113545 (2020)

CH. Lee et al., J Power Sources, 446, 227312 (2020)

S. De Angelis et al., J Mater Chem A Mater, 9, 22102–22113 (2021)
Advanced Hydrogen Crossover Characterization: Closing the Mole Balance through Coupled Anode and Cathode Exhaust Analysis
Authors: Wrubel Jacob A , Duarte Ricardo Filipe Paz Moldes , Pomeroy Elias D , Kowal Andrea , Bender Guido 
Published: December 2024

Hydrogen crossover in proton exchange membrane water electrolysis (PEMWE) is an unwanted phenomenon that leads to both efficiency losses and safety hazards. This issue is expected to worsen as PEMWE systems move towards thinner membranes and high-pressure operation (two straightforward avenues to reduce operating expenses), as well as high turn-down ratios [1]. To address the safety aspect, next-generation PEM architectures are being developed that include a recombination catalyst (e.g., Pt) to consume the H2, i.e. H2 + O2 → H2O, before it makes its way to the anode exhaust. An accurate method for assessing this recombination rate is necessary to evaluate the performance and optimize the recombination catalyst.
In a previous work, we and others demonstrated that the H2 crossover flux can be calculated by analyzing the H2:O2 ratio of the anode exhaust [2 – 4]. However, some assumptions involved in this analysis are not valid in systems with significant H2 + O2 recombination. To get a full picture of the reactions that take place in such systems, it is necessary to analyze the cathode exhaust. By measuring the rates of hydrogen leaving both anode and cathode and comparing them to Faraday’s law, the amount of H2 being consumed in various recombination reactions inside the cell can be quantified.
Figure 1 shows a schematic of the additions required to our previously reported H2 crossover quantification technique. The top exhaust path (grayed out) shows our earlier method for analyzing the anode exhaust. The bottom exhaust path shows the added method that enables analyzing the cathode exhaust. Both techniques use a GC to analyze and quantify the gas composition. In this presentation we will discuss results that verify the technique using H2NEW’s reference FuGeMEA system. We will further demonstrate how the technique can be applied to membranes with recombination catalysts to assess their crossover mitigation capabilities.

References:

[1] A. Badgett, M. Ruth, and B. Pivovar, Electrochemical Power Sources: Fundamentals, Systems, and Applications Hydrogen Production by Water Electrolysis, Elsevier, 2021, pp. 327–364.
[2] J. A. Wrubel, C. Milleville, E. Klein, J. Zack, A. M. Park, and G. Bender, “Estimating the energy requirement for hydrogen production in proton exchange membrane electrolysis cells using rapid operando hydrogen crossover analysis,” Int J Hydrogen Energy, vol. 47, no. 66, pp. 28244–28253, Aug. 2022.
[3] P. Trinke, B. Bensmann, and R. Hanke-Rauschenbach, “Current density effect on hydrogen permeation in PEM water electrolyzers,” Int J Hydrogen Energy, vol. 42, no. 21, pp. 14355–14366, May 2017.
[4] C. Klose et al., “Membrane Interlayer with Pt Recombination Particles for Reduction of the Anodic Hydrogen Content in PEM Water Electrolysis,” J Electrochem Soc, vol. 165, no. 16, pp. F1271–F1277, 2018.

Figure 1
Atomic Layer Deposition of SnO2 Thin Films As Anticorrosion Layers in Proton Exchange Membrane Water Electrolysers (PEMWE)
Authors: Assaud Loïc , Maslouh Haitham , Bechelany Mikhael 
Published: December 2024

The deployment of water electrolysers to generate green hydrogen is a major challenge to decarbonize industry and promote sustainable mobilities. Proton Exchange Membrane Water Electrolysis (PEMWE) is a very attractive technology allowing the production of decarbonized dihydrogen from water molecules at close to ambient temperature (< 100°C), in electrolysers operating at high current densities (>1 A/cm2), compatible with variability of electricity source.
The current limitations of PEM cells concern the porous transport layers (PTL) and the bipolar plates (BPP), particularly in the anodic compartment, which are usually made of titanium because of its resistance against corrosion under the operating conditions of electrolysis [1,2]. However, the highly oxidizing environment of the anode generates a thick oxide layer that passivates the surface of the titanium, resulting in a significant increase of the contact resistance between the elements of the anodic compartment and affecting the overall efficiency of the electrolysis process, while accounting for more than 50% of the total electrolyzer costs. Our multidisciplinary and innovative approach aimed at replacing expensive titanium with stainless steel (316L) - more cost-effective - for BPPs and PTLs which will be coated with protective thin films (SnO2, TiN, TaN) elaborated by atomic layer deposition (ALD) [3]. ALD is a powerful technique allowing to generate highly conformal coatings even on complex substrates such as PTLs, with an accurate control of thickness, chemical composition and structure. In this communication, we will present our first results for optimizing SnO2 thin films grown by ALD on stainless steel 316L and titanium substrates, along with their systematic micro/nano-structural characterization performed by ellipsometry, X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy, etc. The assessment of the anti-corrosion protection of the coatings was carried out ex-situ through stability and corrosion measurements in an acidic environment similar to that of the PEM's operating conditions. Conductivity measurements of the SnO2 thin films were performed to complete the study.
References:
[1] S. Lædre et al., Int. J. Hydrogen Energy. 42 (2017) 2713–2723.
[2] S. Stiber et al., Energy Environ. Sci. 15 (2022) 109.
[3] M. Bechelany et al., Chem. Mater. 30 (2018) 7368–7390.
Ionomer-Free Near-Zero Gap Anion Exchange Membrane Water Electrolyzer Fabricated By in-Situ Modified Catalyst Coated Membrane Method
Authors: Kong Tae-Hoon , Kwon Youngkook 
Published: December 2024

Developing a state-of-the-art anion exchange membrane water electrolyzer (AEMWE) for commercial H2 production remains a great challenge. To enhance the performance and durability of AEMWEs, addressing key limiting factors such as ionomer and internal resistance is essential. The inappropriate use of ionomers in membrane electrode assembly (MEA) fabrication limits the exposure of catalyst-active sites and the transport of gaseous products. Moreover, an unstable phenylic backbone of ionomers oxidizes at high voltages (>2.1 V), causing a localized pH drop at the electrode/electrolyte interface and degrading overall cell performance.[1]

To address these challenges, we developed a novel fabrication method for in-situ deposition of catalyst layers (CLs) directly between anion exchange membrane (AEM) and porous transport layer (PTL) using wet chemical reduction in the AEMWE.[2] This innovative approach enables ionomer-free CL synthesis simultaneously with the fabrication of AEM/CL/PTL-integrated MEAs. This near-zero gap AEMWE exhibited significantly lower cell resistance, compared to AEMWEs assembled by the conventional MEA fabrication methods (catalyst-coated substrate and catalyst-coated membrane), achieving an industrially relevant current density of 1 A cm-2 at a cell voltage of 1.79 Vcell and superior durability over 200 h at 1 A cm-2 in 50 ℃. In addition, it demonstrated the current density of 500 mA cm-2 at a cell voltage of 1.913 Vcell and a low degradation rate of 0.58 mV h-1 for 260 h in continuous electrolysis at a current density of 250 mA cm-2 at 50 °C in feeding ultrapure water.
Furthermore, understanding the degradation mechanisms of each MEA component under operating conditions is crucial for improving stack performance and durability. By integrating the reference electrode in AEMWEs, the degradation of the cathode, anode, and membrane under different electrolyte feeding systems will be discussed.
Reference
[1] D. Li, I. Matanovic, A. S. Lee, E. J. Park, C. Fujimoto, H. T. Chung, Y. S. Kim, ACS Appl. Mater. Interfaces, 11, 10, 9696 (2019).
[2] T. H. Kong, P. Thangavel, S. Shin, S. Kwon, H. Choi, H. Lee, N. Park, J. J. Woo, and Y. Kwon, ACS Energy Lett., 8, 11, 4666 (2023).
Anode Catalyst Layers for AEM-WE: Implementation, Characterisation and Evaluation of Different Synthesis Routes
Authors: Kaufmann Bastian , Hesse Miriam , Pilaski Moritz , Berger Maike , Palkovits Stefan , Palkovits Regina , Welters Martin , Cremer Rainer 
Published: December 2024

The global energy sector's transformation and requisite technological shifts present an unprecedented challenge for politics, industry, and research. Green hydrogen, produced through water electrolysis, is pivotal for storing fluctuating renewable electricity and decarbonizing power demanding industries (e.g. steel production). Current electrolysis technologies do not achieve high efficiencies or require critical materials such as iridium, titanium or flourinated polymers. For these reasons, alkaline electrolyte membrane water electrolysis (AEM-WE) has garnered increased attention from industry and research in recent years. The technology involves many construction principles and advantages of the PEM-WE without its disadvantages. However, further research is necessary to understand electrochemical interactions and technical implementation, especially in catalyst-related topics.
In this work, therefore different types of catalyst layers are prepared and characterized. Depending on the catalyst type distinct preparation methods are applied and the resulting layers are evaluated electrochemically. Full cell experiments are conducted with combined membrane electrode assemblies and in conjunction with electrochemical impedance spectroscopy are used to provide information on contact resistance, electrochemical surface area and overall mass activity.
The applied catalytic materials are made by galvanic deposition, corrosion, precipitation and physical vapour deposition of active species on support materials. Based on the employed preparation method the catalyst implementation and subsequent utilization varies. In particular catalysts from precipitation and PVD-coating were studied in terms of deposition configurations, catalyst loading and a comparison to more widespread catalyst systems. Due to the increase of the specific active surface area by the shape of the synthesised core-shell-like particles, even small amounts of active species could be implemented in highly active layers and thus enable high current densities in optimised electrolysers.

Figure 1
(Invited) Understanding the Corrosion of Titanium Porous Transport Layers and Pt Coatings Using Potential and Time-Resolved Inductively-Coupled Plasma Mass Spectrometry
Authors: Myers Deborah J. , Kropf A. Jeremy , Kariuki Nancy N. , Dang Ngoc K 
Published: December 2024

Titanium is the state-of-the-art material for porous transport layers (PTLs) for proton-exchange membrane water electrolyzers (PEMWEs) due to its stability and intrinsic electrical conductivity. However, titanium can develop an passivating, insulating oxide layer under the conditions of the PEMWE anode, thus reducing the effective electrical conductivity and cell performance.1 Coating the titanium PTL with platinum group metals is typically used to protect against oxidation.2 The purpose of this work is to investigate dissolution rates of titanium PTLs with and without coatings and of the PGM coatings by measuring the concentrations of metallic species in an aqueous electrolyte as a function of applied potential and environment measured using inductively-coupled mass spectrometry (ICP-MS). Time and potential resolution of the dissolution rates were achieved by coupling an aqueous electrolyte electrochemical flow cell with an on-line ICP-MS. These studies are the basis for establishing the thermodynamic and kinetics of degradation processes to be used for modeling the degradation phenomena as a function of electricity profile at the single cell and stack level. Results of ex situ, post-test and operando X-ray absorption spectroscopy characterization of platinum PTL coatings will also be discussed.
Acknowledgements
This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW Consortium. Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC, also under contract DE-AC-02-06CH11357.
References
1. Tuan Linh Doan, Han Eol Lee, Syed Shabbar Hassan Shah, MinJoong Kim, Chang-Hee Kim, Hyun-Seok Cho, and Taekeun Kim, Int. J. Energy Res., 45 (2021) 14207.
2. Chang Liu, Meital Shviro, Guido Bender, Aldo S. Gago, Tobias Morawietz, Michael J. Dzara, Indro Biswas, Pawel Gazdzicki, Zhenye Kang, Sarah F. Zaccarine, Svitlana Pylypenko, K. Andreas Friedrich, Marcelo Carmo, and Werner Lehnert, J. Electrochem. Soc., 170 (2023) 034508.
Controlling Current Distributions in a Hydrogen Powered Fuel Cell Hydroxide Exchange Membrane Carbon Capture Device
Authors: Harrington Justin , Setzler Brian P , Yan Yushan 
Published: December 2024

Climate change is one of the most pressing social issues in the modern day. CO2 is responsible for most of the greenhouse gases which cause temperature rise. To reach the 1.5 °C temperature rise goal of the Paris Agreement 2-20 gigatons of CO2 will need to be removed from the atmosphere annually1. Direct air capture (DAC) of CO2 is a negative emissions technology which has garnered widespread technological and public interest for its ability to help achieve this 2-20 gigatons of removal. A hydrogen powered fuel cell hydroxide exchange membrane carbon capture (HEMCC) device is a recent electrochemical DAC technology that is capable of continuously capturing CO2 from ambient air at room temperature.
Hydrogen powered HEMCCs capture CO2 using fuel cell chemistries – O2 and H2O present in humidified air react at the cathode with electrons to form hydroxides which then react with CO2 in an acid-base equilibrium to form HCO3
- and CO3
2-. HCO3
- and CO3
2- then move across the hydroxide exchange membrane to the anode where they shift back to CO2 and OH-. H2 supplied to the anode then reacts with the OH- to form H2O and electrons. Electrons move from the anode to the cathode either through an external circuit or, if purposefully shorted to remove the need for extraneous cell hardware, through the membrane itself. If the membrane is purposefully shorted current density is controlled by varying flowrates of H2 to the anode and measuring H2 out of the cell
While purposefully shorting the membrane reduces capital costs, it reduces the CO2 capture efficiency of the HEMCC device. This study focuses on nonhomogeneous current distributions as the cause for the reduced efficiency of the HEMCC device, and how increased kinetic and mass transport overpotentials on the anode can be used to control current distributions within a HEMCC device. By controlling current distributions efficiency can be increased to be comparable to that of a non-shorted HEMCC device.

Ozkan, M., Nayak, S. P., Ruiz, A. D. & Jiang, W. Current status and pillars of direct air capture technologies. iScience
25, 103990 (2022).
Iridium Thrifting and Circularity: Perspective, Progress, and Demonstration from an OEM
Authors: Motz Andrew R , Carmo Marcelo , Capuano Christopher B. , Ayers Katherine E. 
Published: December 2024

Proton exchange membrane water electrolysis (PEMWE) is a technology that has promise to help decarbonize the hydrogen sector and thus has recently been receiving significant attention. Incentives across the globe, including in the Hydrogen Hubs in the US and the European Hydrogen Bank, have been announced to support early projects and catalyze the industry. The PEMWE market growth was already starting due to recent technological advances and these incentives are helping further accelerate the industry. This acceleration is evident by the number of press releases on manufacturing capacity expansion and large projects being announced. With this market expansion, the industry will inherently demand more iridium – currently the only commercially viable OER catalyst for PEMWE. The mantra of reduce, reuse, and recycle is being applied to iridium where iridium thrifting (reduce) and circularity (recycle) are focal points.
The first part of this talk will focus on iridium thrifting. Simply reducing the catalyst loading with today’s baseline technology results in performance and durability loss; therefore, advanced materials and technology must be developed to realize the iridium thrifting goals. Performance and durability data will be presented for state-of-the-art catalyst that enable low iridium loadings. The second part of this talk will cover iridium circularity. Various recycling streams exist including manufacturing waste, manufacturing scrap, and end-of-use devices from the field. The value recovery for each of these waste streams will be discussed and data demonstrating full circularity will be presented.
Enhanced Durability and Performance of SOEC Stacks at Intermediate-Low Temperature Operation
Authors: Park Hunmin , Kim Sun-Dong , Choi Yoonseok 
Published: December 2024

Recognizing the urgent need for sustainable and efficient energy technologies, we have investigated the durability of Solid Oxide Electrolysis Cells (SOECs) over a demanding 1000-hour period at a constant temperature of 650°C. A key discovery was that SOECs equipped with advanced conductive coatings on the separators exhibited a significantly lower degradation rate(-0.7%) compared to traditional cells(29.0%). Cells using these coated separators maintained structural integrity and demonstrated excellent performance at low voltages.
Testing under stringent conditions highlighted the exceptional durability of the coated separators, which is essential for large-scale hydrogen production. The low degradation rate and consistent voltage demonstrate the revolutionary potential to enhance the stability and long-term efficiency of SOECs operated at 650°C.
This research proves the critical importance of separator coatings in developing SOECs that perform operate continuously and perform excellently at low voltage levels in intermediate-low temperature conditions. This study is significant as it presents the first instance of a 650°C operating SOEC stack capable of stable, long-term operation over 1000 hours. Such advancements support the introduction of SOECs into the clean energy market and set the stage for the next generation of technologies essential for a sustainable energy future.
Advanced Bipolar Plates for the Next Generation PEM Water Electrolyzers: Flow-Field Design, Fabrication, and Optimization
Authors: Perkins Ethan Matthew , Bonville Leonard J. , Maric Radenka , Bliznakov Stoyan 
Published: December 2024

Flow-fields, responsible for distributing reactants, like water for electrolysis, evenly across the active area of the cell as well as removing by-products, are key to achieving high efficiency and longevity in proton exchange membrane water electrolyzers (PEMWEs). Current problems include the complex interplay between fluid dynamics and electrochemical reactions leading to uneven distribution of reactants, which can cause hot spots and accelerated degradation of the cell components. Furthermore, the geometry of flow channels can result in increased pressure drop and higher energy consumption for the pumping of reactant fluids, directly impacting the overall efficiency and scalability of the technology.
For PEMWEs, hydration of reaction sites in the membrane is a crucial factor that significantly influences their efficiency and performance. This study explores the rapid production and testing of multiple novel flow field geometries, each designed to increase cell performance due to multiple different factors. Each flow-field is designed, fabricated, and tested with a state-of-the- art MEA at operating conditions typical for an industrial electrolyzer. The performance of each flow-field design is compared against all other designs explored. Critical information about the impact of the pressure drop and the flow-field contact area upon the electrode is collected. Using this data, the performance of various flow-field designs is derived and discussed in this work.