IRD Fuel Cells (Denmark)

Abstract The stoichiometric water demand for hydrogen production via electrolysis is modest, yet total water use is often dominated by cooling requirements. While the stoichiometric water demand is fixed by the electrochemical reaction, water requirements for cooling electrolysis varies widely depending on local environmental, meteorological and operating parameters. Despite its increasing prominence in sustainable hydrogen production, the significant variability in cooling water requirements for electrolysis across different climates and regions remains poorly quantified. This work aims to address this gap by using a thermodynamic model tailored to the water intense evaporative cooling technology. We contextualized results by incorporating local water scarcity and renewable capacity factors, enabling comprehensive recommendations for sustainable water management. The results indicate that evaporative cooling systems need special considerations in regions where water electrolysis is driven by high PV potentials, with a different picture for wind driven water electrolysis. This highlights the need for region-specific strategies that balance technology choice with local water availability for upcoming hydrogen export regions to ensure resource-efficient hydrogen production. The insights gained are crucial for shaping policies and practices that ensure both environmental and economic sustainability in the hydrogen economy.

A systematic catalyst loading study reveals the higher catalytic activity of amorphous iridium oxide arises from bulk participation via suggested electrochemical descriptors, while identifying loading-independent intrinsic electrochemical properties.

Understanding the properties of carbon supports is essential for optimizing the performance and durability of Pt‐based catalysts in polymer electrolyte membrane fuel cells (PEMFCs). This review examines recent advances in the characterization and functional role of carbon supports, focusing on porosity, graphitization, and chemical modifications. Key methods used to assess the ordering of carbon phases and structural features are discussed, with attention to how these characteristics influence catalyst behavior. Particular emphasis is placed on the importance of fair comparison between Pt/C catalysts with different carbon supports, ensuring reliable performance assessments. The review then explores the interplay between graphitic and amorphous domains, highlighting how surface chemistry and chemical modifications can affect catalyst activity and stability. The impact of porosity and platinum nanoparticle locality is also examined, with special focus on how pore architecture can offer protection from ionomer‐induced poisoning and inhibit nanoparticle coalescence during operation. Throughout, the review identifies challenges in current characterization techniques and underscores the need for a holistic understanding of support architecture. Finally, it outlines design principles for next‐generation carbon supports that can better stabilize Pt nanoparticles and enhance the overall performance and durability of PEMFC cathodes.

Efforts to improve proton exchange membrane fuel cell (PEMFC) durability are crucial for a hydrogen-based society, but their widespread adoption, especially in heavy-duty vehicles, is limited by membrane degradation from radical attacks. Herein, we report polar-solvent- and water-soluble fullerene derivatives C60(C6H3(OH)2-3,4)5(OH)n and C60(C6H4COOH)5(OH)n (n = 0–13) as radical scavengers which are homogeneously dispersed into the Nafion membranes. The hydroxy and carboxylic acid functional groups in the fullerene derivatives not only improved water solubility but also facilitated proton conductivity and chelating scaffold for Ce ions as co-scavengers. The fabricated Nafion membrane with functionalized fullerene derivatives and the chelation of Ce significantly enhanced durability, delaying membrane degradation for 1050 h compared to pristine Nafion membrane, which degraded with 100 h. It also reduced the F⁻ ion release rate to 10% of that of the reference Nafion membrane. These findings highlight the potential of functionalized fullerenes and their derivatives as effective PEMFC additives, enhancing both performance and durability for wider hydrogen energy system adoption. The limited lifetime of proton exchange membranes, due to radical attacks, hinders the broader adoption of hydrogen energy in heavy-duty vehicles. Here, membrane durability is enhanced by incorporating water-soluble fullerene derivatives and Ce ions, extending lifespan and reducing degradation.

ABSTRACT Iridium and platinum have adjacent atomic numbers that account for the proximity of their x‐ray transition energies and thus the overlapping peaks in their x‐ray fluorescence spectra. This presents a challenge for the quantitative elemental analysis of IrO 2 ⋅2H 2 O‐Pt binary catalyst coatings, especially where the ‘Fundamental Parameter’ method is unavailable, as in the Niton XL3t energy dispersive x‐ray fluorescence analyser. Therefore, we studied the spectral resolution of the Lα, Lη and Lβ peaks for Ir and Pt as recorded on a Niton XL3t to identify the optimal regions of interest. These ROIs were used to measure a set of discrete Ir and Pt standard samples—in which the elemental loadings were derived from the mass and formulation of the catalyst coatings—for constructing correlation graphs to enable the conversion of x‐ray intensity data (cps μA −1 ) to elemental loading (mg cm −2 ). These correlation data were fitted to a quadratic regression. The overall measurement uncertainty for the elemental loadings was determined by combining the residual standard error in the quadratic regression with the uncertainty for the elemental loadings used in the construction of the correlation graph, yielding ±0.07 mg cm −2 for Ir (ROI: 9.00–9.18 keV) and ± 0.04 mg cm −2 for Pt (ROI: 9.36–9.65 keV). The quadratic functions and their corresponding ROIs were programmed into the analyser to measure a set of IrO 2 ⋅2H 2 OPt binary standard samples. This revealed a strong agreement between the elemental loadings as displayed on the analyser and those derived from the mass and formulation of these standard samples.

A mechanistic understanding of carbon corrosion in polymer electrolyte fuel cells (PEFCs) is required to design catalyst layers that are durable. Electrochemical oxidation of carbon occurs during uncontrolled startup and shutdown events of PEFCs leading to multitude of degradation events, including loss of electrochemical surface area (ECSA), pore structure collapse, Pt detachment, loss in ionomer and others. To understand carbon corrosion physics and resulting degradation mechanisms a detailed electrochemical characterization is needed to probe interfaces between Pt-ionomer, carbon-ionomer and to measure transport properties and the ECSA in the catalyst layer. In this presentation we will provide an overview of carbon corrosion understanding and our approaches to quantify the sequence of events. In these studies, PEFCs were subjected to the Department of Energy carbon corrosion accelerated stress test (AST) protocol. Various electrochemical techniques were used to describe interfaces and morphology, as well as transport properties for the cells at different stages of the AST. ECSA measurements, polarization curves, CO-displacement/stripping to determine sulfonic acid group coverage in dry and wet conditions, electrochemical impedance spectroscopy, oxygen transport resistance measurements and other techniques were used. In addition, physical characterization methods at the beginning of life (BOL) and end of life (EOL) were used, such as micro x-ray fluorescence mapping, focused ion beam scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy. A combination of electrochemical and physicochemical methods revealed that amorphous carbon oxidizes first, after which Pt detach resulting in the loss of the ECSA, followed by severe structure collapse, resulting in a poor oxygen transport resistance. We extend the study to carbon supports that are more graphitized to alleviate some of the issues observed with amorphous carbon support.

Here, we report a study on the structural characteristics of membrane electrode assembly (MEA) samples obtained from a low-temperature (LT) polymer electrolyte membrane (PEM) fuel cell (FC) stack subjected to long-term durability testing for ∼18,500 h of nominal operation along with ∼900 on/off cycles accumulated over the operation time, with the total power production being 3.39 kW h/cm2 of MEA and the overall degradation being 87% based on performance loss. The chemical and physical states of the degraded MEAs were investigated through structural characterizations aiming to probe their different components, namely the cathode and anode electrocatalysts, the Nafion ionomer in the catalyst layers (CLs), the gas diffusion layers (GDLs), and the PEM. Surprisingly, X-ray diffraction and electron microscopy studies suggested no significant degradation of the electrocatalysts. Similarly, the cathode and anode GDLs exhibited no significant change in porosity and structure as indicated by BET analysis and helium ion microscopy. Nevertheless, X-ray fluorescence spectroscopy, elemental analysis through a CHNS analyzer, and comprehensive investigations by X-ray photoelectron spectroscopy suggested significant degradation of the Nafion, especially in terms of sulfur content, that is, the abundance of the -SO3- groups responsible for H+ conduction. Hence, the degradation of the Nafion, in both of the CLs and in the PEM, was found to be the principal mechanism for performance degradation, while the Pt/C catalyst degradation in terms of particle size enlargement or mass loss was minimal. The study suggests that under real-life operating conditions, ionomer degradation plays a more significant role than electrocatalyst degradation in LT-PEMFCs, in contrast to many scientific studies under artificial stress conditions. Mitigation of the ionomer degradation must be emphasized as a strategy to improve the PEMFC's durability.

The maturity of the current polymer electrolyte membrane fuel cells (PEMFCs) has been product of the considerable scientific and industrial effort devoted to developing highly efficient and reliable versions of this technology, resulting in its increased application in the transportation and energy generation sectors. Fuel cells are one of the most advantageous solutions for clean energy applications due to their near-zero-emission, high efficiency, low maintenance cost, and high energy density. PEMFCs produce electricity through the electrochemical reaction of hydrogen and oxygen (or air) taking place in the Membrane Electrode Assembly (MEA) by converting chemical energy of the hydrogen oxidation and oxygen reduction into electrical energy with water as a byproduct. However, producing oxygen reduction reaction (ORR) catalysts with high performance at scale is still a challenge that needs to be tackled to enable an increment in energy generation of this technology. Additionally, tunability of the materials at the core of this technology is essential to meet the demands of the specific application and operating conditions. Here we investigate commercially available ORR catalysts based on platinum nanoparticles (Pt-NPs) supported on nitrogen-functionalized carbon (Engineered Carbon SupportsTM, ECSTM) produced by Pajarito Powder, LLC at scale. The ORR performance of three MEAs made with different Pt/ECS catalysts, by IRD Fuel Cells, LLC was studied under low relative humidity conditions, exhibiting competitive performance, and reaching current densities between 1.8 and 1.3 A/cm2 at 0.6 V, at extremely low loading of Pt – 0.1 mgPt cm-2. The physicochemical properties of these Pt/ECS catalysts alongside their Pt-free ECSTM analogue carbon support materials were comprehensively studied. For this purpose, several characterization techniques were used, such: X-ray diffraction, Raman spectroscopy, and transmission electron microscopy (TEM) to investigate structural and morphological properties, X-ray photoelectron spectroscopy to determine the surface composition and chemical properties, thermogravimetric analysis to evaluate thermal oxidation properties, and nitrogen sorption to determine the surface area and porosity, of the materials. This thorough characterization enabled us to determine that the best performing catalyst in the conditions used in this work have the highest surface area and the highest concentration of surface dopants (nitrogen and oxygen). Although, catalyst supported on lower surface area carbon, but with higher graphitic content, also exhibited competitive performance that can be exploited in applications where more corrosion-resistant carbon is needed. Finally, based on the highly competitive MEA performance for the three Pt/ECS catalysts supported on these carbons, our work demonstrates that these carbon supports (developed by Pajarito Powder, LLC) with engineered morphology and composition fabricated through VariPoreTM synthetic technology can result in tunable properties suitable for a targeted application. We can conclude that these commercially available materials can be adapted through modification of the versatile synthesis platform to tune the physiochemical properties of carbons for other applications and conditions.

Invited for this month's cover is the collaborative work among Univ. of Milano-Bicocca, Ricerca sul Sistema Energetico S.p.A., Univ. degli Studi di Milano, Univ. of California Irvine, Univ. of New Mexico, CNRS Toulouse. Technische Univ. Braunschweig, Aquacycl LLC, J. Craig Venter Institute, Helmholtz-Centre for Environmental Research. The image shows a sketch of a microbial fuel cell and a target indicating the need of developing common standards for the field of microbial electrochemical technologies. The Full Paper itself is available at 10.1002/cssc.202100294.

The growing societal and political focus on the use of environmentally friendly technologies has led to an ever-increasing interest in electrolysis technologies in the scientific communities. This development is reflected by the plethora of candidate catalysts for the hydrogen and oxygen evolution reactions, as well as the CO2 reduction reaction, reported in the literature. However, almost none of them entered the stage of application yet. Likewise, the reports on process engineering inadequately address the utilization of these catalysts, as well as electrode and cell concepts, that might be suitable for the market. Evidently, a closer collaboration between chemists and engineers from industry and academia is desirable to speed up the development of these disruptive technologies. Herein, we elucidate the critical parameters and highlight the necessary aspects to accelerate the development of industrially relevant catalysts capable of fulfilling the forthcoming challenges related to energy conversion and storage. The aim of this Perspective, composed by industrial and academic partners, is to critically question current undertakings and to encourage researchers to strike interdisciplinary research pathways.