bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring the Effects Brought By a Drug on Myocardial Cells Using Field Effect Transistor (FET) Based Sensing Platform
Authors: Tsai Shu-Yi , Paulose Akhil K , Kalaimani Vishal Mani , Lin Chia Kai , Wang Yu-Lin
Published: September 2023

Abstract: Ion channels are the membrane proteins that modulate the active flow of ions between cellular environment. These therapeutic targets are expressed in every active cell and can be used as important targets for cellular changes. The ion channels play an important role in different physiological processes including blood regulation, cell proliferation, nerve relaxation, etc. Various cardiac and neurological diseases have been reported to be related to ion channel regulation. They are brought through by the ion channel mutations. Several techniques are currently deployed for monitoring drug effectiveness of ion channels. Among these techniques, patch clamp technology is considered as a golden standard for monitoring the ion channel function. Unfortunately, the conventional patch clamp technologies are not enough to be employed in the early stages of drug discovery. Similarly, serval fluorescence detection methods and combination technologies have been developed for calcium ion channel detection. These assays are not suitable for large scale detection due to less selectivity and sensitivity.

At present, field-effect transistor-based biosensors (BioFETs) have been widely employed in various applications due to their non-invasive detection, and high sensitivity. In this work, we adopted an extended gated EDL-FET platform for rapid drug screening on myocardial cell lines (H9c2). The drug effectiveness was studied by tested nifedipine on myocardial cells which were mounted over an EDL-FET platform. Two different surface conditions were studied using Ca2+ treatment and the capability the of EDL-FET sensor as a drug screening platform was discussed.

Surface functionalization and Measurements

An extended gate chip was used as the sensor array. Before probe immobilization, the sensor electrode was treated with oxygen plasma. Cell attachment over the sensor platform was facilitated using a glycoprotein- Fibronectin. Traut’s reagent was used to modify fibronectin to initiate the covalent attachment to the sensor surface. Optical images and electrical readings were taken to ensure proper functionalization of the fibronectin-attached surface before the cells were seeded over it. Myocardial cells (H9c2 cells), removed from their culture media, were incubated over the functionalized electrodes for ~2 hours following which, electrical measurements were taken to establish a baseline reading using the BioFET device. Different concentrations of nifedipine [0 to 50 μM] and calcium ions [18 μM to 1.8 mM] were used to make testing solutions, which were used for monitoring various changes occurring on the ion channels of the myocardial cells.

Figure 1
In-Situ Generation of H2O2 from Bismuth Telluride (Bi2Te3) Cubes for Instant Hand Sanitizer
Authors: Sharma Manish Kumar , Khan Imran , Chueh Yu-Lun , Lin Zong-Hong
Published: September 2023

COVID-19 was discovered in Hubei Province, China in December 2019. According to World Health Organization reports, on December 2, 2022, this disease spreads to at least 200 countries, infecting more than 640 million people which raised beyond 6 million deaths globally. Efforts are being made to alleviate the number of COVID cases by development of vaccines. As per WHO guidelines, the community should follow some precautions even after taking vaccine, such as physical distancing, wearing a mask, avoiding crowds, and regularly sanitizing hands. Hand sanitization is recognized as the most effective way to prevent the spreading of infectious diseases (such as COVID-19). So, hand sanitizer has become one of the most sought-after products in the world. Mostly hand sanitizer contains alcohol (more than 60%) which damages the outer layer of skin and kills both harmful as well as protective microbes present on skin. To overcome these issues, Hydrogen peroxide (H2O2) can be considered as an alternative choice having excellent antibacterial action against a wide range of microorganisms without harming the skin. So, we demonstrated repeatedly generation of H2O2 by placing bismuth telluride (Bi2Te3) cubes in sanitizer bottle filled with hot water (100 oC) from water dispenser. H2O2 is one the most stable radicals as compared to other reactive oxygen species (ROS). Even after 12 hours, H2O2 is still exists in the sanitizer bottle which is examined by fluorescence spectroscopy. 5 sprays of H2O2 show 100% antibacterial activity for E.Coli survival rate as compared to 75% ethanol sanitizer. This study demonstrated Bi2Te3 cubes for repeatedly generation of H2O2 as instant sanitizer via hot water from water dispenser which can be convenient to maintain hygiene and to prevent from infectious diseases such as COVID-19.
The Combination of Upconversion Nanoparticles and Photodynamic Therapy for Alzheimer’s Disease Treatment in Real-Time Monitoring
Authors: Lin Yu Chien , Wang Yu-Rong , Huang Tai-Ling , Chen Jung-Chih
Published: September 2023

Alzheimer’s Disease (AD) consumes many medical resources in disease caring and delays symptoms. The aggregation of amyloid-beta (Aβ) is regarded as one of the foci of AD. It will form oligomers and polymerize into fibrotic neurofibrillary tangles leading to AD. Many research has focused on the diagnosis and risk factors of Aβ aggregation, trying to reverse the situation of Aβ aggregation by various approaches. However, there are no advantageous solutions that have been developed so far. Establishing a system from monitoring to controlling Aβ aggregation is urgently needed as a new approach for AD treatment. Once Aβ aggregation can be monitored and controlled to oxide and degrade it before forming oligomers. It will bring huge benefits to AD treatment. Therefore, this study combines photodynamic therapy (PDT) and quartz crystal micro-scale (QCM) techniques to realize the degradation of Aβ and monitor whether Aβ is degraded, and establish a complete system.

PDT has been applied in the medical field, especially for cancer treatment which induced oxidative stress results in different levels of protein oxidation. However, the limited excitation source limits the application of PDT, for example, the insufficient penetration depth of the excitation source prevents in vivo treatment of AD. Therefore, it needs to be combined with other materials to achieve in-depth treatment. This study proposes to modify photosensitizers on upconverting nanoparticles (UCNPs), and use 980 nm near-infrared to excite and then emit visible light to perform PDT. The combination of PDT and UCNPs generates the reactive oxygen species (ROS) to oxide Aβ and further degrade Aβ aggregation. However, most of the lanthanide metals and photosensitizers doped UCNPs are cytotoxic. Thus, Rose Bengal (RB) was selected as the reactive photosensitizer in this system owing to it being a metal-free, non-toxic, and widely available material. Also, it has been confirmed through research that RB can effectively transfer energy to form 1O2. To further ensure that material can be used in AD treatment, modify the SiO2 shell on the surface of UCNP to improve biocompatibility. The experimental results show that the cell survival rate can be maintained at about 80% when the concentration of UCNP reaches 25mg/mL.

The degradation of the Aβ peptide can be monitored using the QCM technique. QCM was applied for monitoring the differences in the oscillation frequency by the degradation of the Aβ peptide attached to UCNPs. Meanwhile, the DCFH-DA ROS assay kit was applied to estimate the Aβ peptide oxidation level. The results of this study show that the combination of UCNPs for PDT can effectively oxidize and degrade Aβ, and utilizing QCM and ROS assay kit can monitor the level of Aβ oxidation and degradation in real-time. The establishment of this system can help more potential AD patients, providing a diagnostic and treatment method.

Figure 1
(Invited) bionic Composite Films for Biomechanical Energy Harvesting and Self-Powered Sensing Applications
Authors: Lin Zong-Hong , Parashar Parag
Published: September 2023

Triboelectric nanogenerators (TENGs) are novel and sustainable devices for harvesting ambient energy for many technological-based applications. However, extreme friction wear of triboelectric layers severely limits their long-term electrical stability and mechanical reliability, restricting the applicability of TENGs for low-frequency mechanical energy harvesting. Herein, we report novel bionic composite (BC) films, inspired by the structures and compositions of bioskins, as wear-resistant triboelectric contact layers for TENGs. We demonstrated that the proposed BC films has superior charge transfer capability, high wear resistance, and maintained long-term stable outputs compared to commercially available films. These works provide an effective strategy to reduce material abrasion by exploiting unique characteristics of the bionic materials, and lays a foundation for effective environmental energy harvesting toward practical applications.

Figure 1
(Invited) hand-Held Florescence Microscope for Single Micro/Nano Particle Imaging
Authors: Sami Muhammad , Hassan Umer
Published: September 2023

Fluorescence microscopes are commonly used to detect micro and nano biological entities (blood cells, microbes, functionalized particles etc.). Several experimental assays have been developed for biomarker measurements using this microscopy instrument. Common examples include cell viability analysis, surface receptor based specific blood cell enumeration, phagocytosis determination etc. However, the laboratory-based bench top fluorescence microscope suffers from high capital cost, maintenance, experienced staff for its operation and lack of portability. To address several of these challenges, here we have developed a hand-held, portable, 3D printed fluorescence microscope to enable single cell enumeration and nanoparticle imaging operated by smartphone.

3D printed platform is composed of top and bottom portions. The bottom portion includes excitation optics including an LED and excitation filter. While the top portion houses an emission filter, and a lens, while a smartphone can be placed on top portion for imaging. The excitation and emission filters can be swapped out for different fluorophores used. We have used the platform for imaging leukocytes collected from the whole blood. Blood samples were procured from Robert Wood Johnson Medical Hospital. We ran the leukocytes on our photonics platform and laboratory florescence microscope concurrently for a comparative analysis and found a high correlation of R2 = 0.99 in between cell counting results. Further, swapping different lenses can achieve high resolution for the imaging system. The resolution was verified by US Airforce Resolution Chart. This allowed us to image fluorescent nanoparticles up to 800nm at various concentrations and excitation modalities.

This platform can be used for single-cell analysis, specific leukocytes enumeration and nanoparticles imaging. The demonstrated results can enable significant applications to develop many biomedical and diagnostic assays.
High-Precision Microdisk Laser Particles by Active Photoelectrochemical Etching for Cell Barcoding
Authors: Sarkar Debarghya , Dannenberg Paul , Martino Nicola , Kim Kwon-Hyeon , Yun Seok-Hyun
Published: September 2023

To study the spatio-temporal evolution of individual cells in an intact tissue or other specific microenvironment, organic fluorophores are widely used. Owing to the broad emission linewidth (full width at half maximum exceeding 50 nm) of the organic fluorophore molecules, only limited number of fluorophores with non-overlapping spectral signatures can be simultaneously observed on the spectral range of the spectrometer. Thus there is a need of optical probes of deterministic colors with non-overlapping narrow spectral signatures. In the recent past, a new class of biophotonic tool – called laser particles – has emerged, which is unique in terms of its narrow spectral linewidth arising from lasing. In the previous studies, however, the lasing wavelength of the individual laser particles has been random. In this presentation, we shall report the first step towards addressing this, by demonstrating fabrication of InGaAsP microdisk laser particles by active photoelectrochemical etching to lase in distinct deterministic narrow-band “colors”. The experimental pathway supported by a theoretical model to explain the results, would be presented. By careful choice of the material system coupled with the design of the disk geometry, we were able to demonstrate multiple unique “color bands” of single-mode lasing of all microdisks simultaneously emitting in the same narrow spectral band. Transferring these wavelength-tuned microdisks onto a PDMS substrate, we create free-standing precision laser particles. This technology could potentially open up a viable avenue to simultaneously identify and image over 20 unique biomarkers in the same spectral bandwidth as currently provided by 4 organic fluorophores.
Additive Carbon Dots Nanocrystals for Enhancement of the Efficiency of Dye-Sensitized Solar Cell in Energy Applications Technology
Authors: Watiro Getachew Kuma
Published: September 2023

Demand for solar energy is constantly increasing and it is widely available on the earth’s surface. Photovoltaic technology is one of the most capable of all viable energy technology and is seen as a promising approach to the control era as readily available and has zero carbon emissions. Inexpensive and versatile solar cells have achieved the conversion efficiency and long life of dye-sensitized solar cells, improving the conversion efficiency from the sun to electricity. DSSCs (Dye-Sensitized Solar Cells) have received a lot of attention for Various potential commercial uses such as mobile devices and portable electronic devices, as well as integrated solar cell modules. The systematic reviews were used to show the critical impact of additive C-dots in the Dye-Sensitized solar cell for energy application technology. This research focuses on the following methods to synthesize nanoparticles such as a polyol, calcination, and hydrothermal technique. In addition to these, there are additives C-dots by the Hydrothermal method. This study deals with the progressive development of DSSC in photovoltaic technology. The photoconversion efficiency of the applications of single and heterojunction devices was used (ZnO, NiO, and NiO/ZnO/N719), and applied some additives C-dots (ZnO/C-dots/N719, NiO/C-dots/N719, and NiO/ZnO/C-dots/N719) and the effects of C-dots were reviewed. More than all, the technology of DSSC with C-dots enhances efficiency Finally, recommendations have been made for future research on the application of DSSC with the use of this additive.
Performance and Stability of Molten Carbonate Fuel Cell Cathode Electrode Under Carbon Capture Endurance Tests
Authors: Hilmi Abdelkader , Geary Timothy , Franco Adam , Yuh Chao-Yi , Willman Carl
Published: September 2023

Introduction

The molten carbonate fuel cell (MCFC) has emerged as one of the promising alternatives for carbon capture from industrial and power generation CO2 sources. MCFC technology is less energy-intensive compared to conventional amine scrubbing that requires a significant amount of energy (steam) for solvent regeneration process.

MCFC has been commercially used for distributed power generation, however its use in carbon capture applications has been limited to development activities and a few demonstrations during the past decades. The electrochemical reactions taking place during cell operation involve the CO2 transfer from cathode to anode in the form of carbonate ions resulting in a gas stream with high CO2 concentration on the anode exhaust. Therefore, MCFC stack systems can be combined with conventional combustion-powered generators (coal and/or natural gas-based power plants) for simultaneous CO2 separation, power and hydrogen generation.

CO2 capture applications will typically take in flue gas from industrial furnaces, coal and gas fired combined cycle plants as the cathode inlet gas stream having low CO2 concentrations ranging from 4% to 10% by volume and high CO2 utilization (>90%). These CO2-lean conditions may pose a challenge for attaining good mass-transfer performance and life stability, therefore innovative approaches are needed in terms of hardware design and cathode structure to achieve long-term stability.

FCE has tested numerous single cells (250 cm2) and technology stacks (30 kW) under carbon capture operating conditions (4-8% CO2 in the cathode inlet as opposed to >12% in baseline MCFC systems) to understand impact of design parameters on performance, life, and to investigate design solutions for further enhancement. Figure 1 highlights the effect of cathode water content on CO2 utilization. It appears that differences exist between the ideal and measured CO2 utilizations, indicating that less CO2 is transferring from the cathode to anode than expected. This CO2 transference reduction becomes more pronounced with higher water concentration, suggesting that a species other than CO3
2- ion, likely hydroxide (OH- ion), may be generated and transported through the electrolyte matrix.

This paper will review the cathode material stability and electrochemical performance under long-term carbon-capture operation. The effect of parameters such as water content, gas composition, utilization, and electrolyte chemistry, as well as approaches to enhance the CO2 capture efficiency and life, will be discussed.

Figure 1
Fundamental Insights into Reaction Centers and Catalytic Mechanisms of Ni- and Co-Based Layered Oxyhydroxides for the Oxygen Evolution Reaction
Authors: Zeng Zhenhua , Dionigi Fabio , Zhu Jing , Liang Junwu , Li Wei-Xue , Strasser Peter , Greeley Jeffrey
Published: September 2023

Water splitting to generate green H2 fuel and O2 is essential for global CO2 reductions toward net-zero emissions. In this process, however, O2 generation at the anode through the oxygen evolution reaction (OER) is inherently slower by orders of magnitude than H2 generation at the cathode. Thus, improving OER efficiency has been a major effort in electrolysis. Ni-based and Co-based layered hydroxides are among the most active and studied non-previous catalysts in alkaline electrolytes. Although tremendous advances have been made toward improving the activity and the stability of the catalysts over the past decade, there is still a lack of fundamental insights into active sites and reaction mechanisms, which has hindered the establishment of structure-property relationships.

This talk will first provide fundamental insights into reaction centers and catalytic mechanisms of classic Ni oxyhydroxides and Co oxyhydroxides with and without ligand intercalation. We will further discuss the multiple-site synergy in Ni- and Co-based layered double hydroxides (LDH) and ternary hydroxides. We will show that the OER proceeds via a Mars van Krevelen mechanism, starting with the oxidation of bridge OH at the reaction centers with dual metal sites, i.e., M1-OH-M2. We will demonstrate that, to approach the minimum overpotential dictated by a specific OH-OOH scaling relationship, the key is to break the OH-O scaling relationship. A possible route is to form binary metal oxyhydroxides with dual metal sites at the reaction centers or introduce a third element into NiFe LDH or CoFe LDH. If time permits, We will further discuss the role of the non-covalent interaction and polaron-like electronic states in promoting OER at M1-OH-M2 centers.
Faraday Efficiency Study of Pressurized Alkaline Water Electrolyzer
Authors: Zhang Jian (Jim) , Bie Zhenwu , Zhang Huayong
Published: September 2023

According to a BloombergNEF report, China is the largest green hydrogen market, accounting for about 60% of the expected global electrolysis volume in 2022-2023. More than 90% of these electrolyzers are pressurized alkaline water electrolyzers (AWE), like the classic design of Lurgi. AWE manufacturers and end-users place great emphasis on advanced electrodes and membranes to improve power efficiency, and often using 100% Faraday efficiency to calculate current density-based yields.

As an end-user, the authors investigated a combination of real AWE operating data and electrochemical engineering principles and discovered that Faraday efficiencies were around 85-93%. Therefore, Aspen ACM simulation models were developed based on detailed internal structures and configurations that well corresponded with plant data, suggesting that many AWE manufacturers exaggerate Faradic efficiencies by to 10%.

Some low-cost design improvements are proposed for the bipolar plate and manifold alkali channels, which can improve the Faradaic efficiency by 5-7%, producing higher power efficiency especially when connected to a renewable power source at low loads.
(Invited) Clean Hydrogen: From Colors to Emissions
Authors: Kusoglu Ahmet
Published: September 2023

With ever-growing need for decarbonization, the role of (clean) hydrogen in clean energy transition has been gaining more interest and recognized at many levels, from global and sectoral climate goals and targets to clean energy bills and many roadmaps to net-zero scenarios, all of which necessitate a clear, unambiguous definition for clean hydrogen. This talk aims to expand the dialogue on the clean hydrogen with a focus on transitioning from traditional color-coded descriptions to new definitions that account for carbon intensity of the hydrogen production. The limitations of the color-coding concept will be discussed by providing a refined critique and assessment of categorizing hydrogen production pathways within the context of associated carbon intensity from a life-cycle perspective. Key findings and projections from recent major reports and roadmaps will also be highlighted with key numbers and targets to elucidate the role of hydrogen in transforming the decarbonization of many key sectors.
(Invited) Challenges and Opportunities of Alkaline Water Electrolysis
Authors: de Groot Thijs Theodorus
Published: September 2023

Alkaline water electrolysis has been operated on 100+ MW scale in the 20th century powered by hydropower. Because of this history, the technology is often regarded as a mature technology with limited improvement potential that is less suitable for flexible operation. As a result most research efforts in the field of water electrolysis focus on other technologies such as PEM, solid oxide and AEM electrolysis. This is a pity, since alkaline electrolysis is very well positioned to be deployed on large-scale for the production of green hydrogen in the coming decades. Main reason is that in contrast to the other technologies, alkaline technology does not depend on scarce and/or expensive noble or rare earth metals. Also, the use of a diaphragm instead of a membrane makes the technology more robust.

Yet, to enable the large-scale deployment of alkaline electrolysis for production of green hydrogen from renewable electricity certain technical challenges need to be overcome. These include safety challenges associated with rare scenarios where hydrogen and oxygen can mix, flexibility limitations associated with gas crossover limiting the minimum load of the plant, and durability challenges resulting from frequent shutdowns of electrolyzers. In principle all these challenges can be overcome by rigorous plant design and the selection of suitable diaphragm and electrode materials, but they do require research efforts.

Next to that, there is room to significantly drive down the costs of green hydrogen produced by alkaline electrolyzers. Traditionally, alkaline electrolyzers have been operated at low current densities of 0.2-0.4 A cm-2. This was related to the high ohmic drop associated with the use of thick diaphragms and non-zero-gap cell designs. Presently, advanced alkaline electrolyzers are under development that can operate at significantly higher current densities (~1 A cm-2) through the use of thinner diaphragms, zero-gap cell designs and improved electrode materials. Operation at these increased current densities increases the output of alkaline electrolyzers and in this way can effectively reduce the costs and footprint of water electrolysis plants. Yet, the use of thinner diaphragms and advanced electrodes also creates new challenges, since they can lead to increased gas crossover and vulnerability to impurities and reverse currents that occur upon the shutdown of electrolyzers.

In this presentation the fundamentals of alkaline water electrolysis will be discussed. These include overpotentials and durability of electrode coatings, the role of electrolyte impurities, ohmic resistance, gas crossover through the diaphragm, the influence of operating temperature and pressure, the effect of bubbles, and the influence stray currents resulting from the manifold design. These fundamentals will be translated into a potential design for the perfect alkaline electrolyzer.

Figure:alkaline electrolyzers operational in Norway in 1931. Source: Norsk Industriarbeidermuseum

Figure 1
Multi-Scale Simulations of Bubble Transport in an Alkaline Water Electrolyzer
Authors: Kanemoto Ryo , Suwa Hideki , Tsukase Naruhisa , Araki Takuto , Mitsushima Shigenori
Published: September 2023

The existence of bubbles can lead to the loss of performance by decreasing the electrochemically active surface area and disrupting the transport of hydroxide ions. These effects caused by the bubbles have yet to be sufficiently clarified. A comprehensive understanding of the mechanisms of dynamics inside an electrolyzer from the molecular scale up to the whole electrolyzer scale is needed. Furthermore, establishing relations between these dynamics at a wide range of scales is important. In this study, numerical simulations of bubble transport coupling fluid dynamics, mass transport and electrochemical reactions were conducted on micro and macro scales, respectively. The micro scale bubble simulation (Fig. 1(a)) incorporates the concentration field of the chemical species into the numerical model and deals with how bubbles grow on and detach from an electrode. In this model, the chemical species generated by the electrochemical reactions dissolve into the liquid phase, and their transfer into the gas phase leads to bubble growth. Since the spatial size distribution of the bubbles can be one of the factors that affect electrolysis performance, in the macro scale bubble simulation (Fig. 1(b)), we study how different sizes of bubbles are transported and distributed inside the electrolyzer. To simulate this phenomenon, a four-phase flow analysis is performed in which small, medium, and large diameters are selected as representatives of bubble diameters, and each is treated as a different phase.

[Acknowledgements]

This study was based on results obtained from the Development of Fundamental Technology for Advancement of Water Electrolysis Hydrogen Production in Advancement of Hydrogen Technologies and Utilization Project (P14021) commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

Fig. 1 Simulation systems of bubble transport at (a) micro scale and (b) macro scale.

Figure 1
Modelling of a Proton-Exchange Membrane Electrolysis Cell with Liquid-Fed Cathode
Authors: Gerhardt Michael Robert , Østenstad Jenny S , Raynaud Xavier , Barnett Alejandro O
Published: September 2023

Conventional proton-exchange membrane (PEM) water electrolysers use much thicker membranes (>175 µm) than their PEM fuel cell counterparts (<25 µm), which reduces hydrogen crossover but also reduces electrolyzer efficiency due to the increased Ohmic resistance1. Reduction of hydrogen crossover is critical in conventional systems to avoid buildup of hydrogen in the anode above the lower explosive limit. Due to the use of liquid water at the anode in conventional systems, the anode cannot be flushed with air or an inert gas to reduce the hydrogen concentration.

If the liquid water supply is moved to the cathode, the anode can be easily purged with air, reducing the safety concern related to hydrogen crossover. Proof-of-concept experiments2 have demonstrated the viability of this approach, but many open questions remain regarding the interplay between water transport, water consumption, membrane hydration, and cell performance, as well as understanding what components and properties are most important in improving the efficiency of such a device.

In this work, a framework for modelling of PEM electrolysis cells will be outlined, with special attention to wet and dry anode conditions. The model will be used to provide guidance for optimizing system performance while contributing to understanding of local processes inside an electrolysis cell such as water transport, heat generation, reaction distribution, and bubble formation. We study the impact of various design and operational choices, such as membrane thicknesses, PTL structure, air feed humidity, and differential pressure operation, on the rate of water transport from cathode to anode and on overall cell polarization performance. Using these results, we provide design recommendations for PEM electrolysers with liquid-fed cathodes. Finally, progress towards an open-source implementation of this model will be discussed.

This work has been performed within the HOPE (Revolutionizing Green Hydrogen Production with Next Generation PEM Water Electrolyser Electrodes) and HYSTACK (Low cost, high efficiency PEM electrolyser stack) projects financially supported by the Research Council of Norway under project numbers 325873 and 321466, respectively.

Ayers, K. et al. Perspectives on Low-Temperature Electrolysis and Potential for Renewable Hydrogen at Scale. Annu. Rev. Chem. Biomol. Eng.
10, 219–239 (2019).

Barnett, A. O. & Thomassen, M. S. Method for producing hydrogen in a PEM water electrolyser system, PEM water electrolyser cell, stack and system. Patent No.: WO 2019/009732. EP3649276B1. US11408081B2.
(Invited) Overall Research on Electrode Coating Processes (OREO) - the Role of Imaging and Spectroscopy in Scale-up Fabrication of Low Temperature Water Electrolyzers
Authors: Jankovic Jasna , Ahmadi Maryam , Batool Mariah , Ney Linda , Franzetti Irene , Horstmann Jeronimo , Khandavalli Sunilkumar , Foster Jayson , O. Godoy Andres , Mauger Scott A , Pylypenko Svitlana , Lickert Thomas , Zamel Nada , Smolinka Tom , Groos Ulf
Published: September 2023

With the recent trends in hydrogen technologies, scale-up fabrication of membrane electrode assemblies (MEAs) for the electrochemical systems such as fuel cells and electrolyzers is gaining significant attention. Companies and researchers are focusing on diverse large-scale electrode fabrication processes, such as roll-to-roll and screen-printing. However, optimizing such processes is not trivial, and a number of parameters, including but not limited to catalyst type, solvent, ink mixing, electrode coating and drying, play a role in the quality of the final product. Correlations between the fabrication parameters and resulting electrode microstructure, properties and performance are important to understand, in order to better control the processes. Imaging and spectroscopy techniques play an important role in this understanding, starting from catalysts, inks and all the way to the electrodes. Information about catalyst distribution, composition, and surface chemistry can be correlated to ink characteristics, and finally to electrode structure, component distribution and properties, and their effect on MEA performance can be investigated.

In this talk, a collaborative work between four institutions, University of Connecticut, Colorado School of Mines, National Renewable Energy Lab and Fraunhofer ISE, within a project on Overall Research on Electrode Coating Processes (OREO), is discussed, with the focus on low temperature water electrolyzers scale-up fabrication and characterization. The talk will especially focus on the role of advanced microcopy and spectroscopy in the characterization of catalyst powders, inks and electrodes.
Electron Microscopy Investigation of Porous Transport Layer Coatings
Authors: Arregui-Mena David , Cullen David A. , Domingo Marimon Neus , Stelmacovich Genevieve , Pylypenko Svitlana , Ware Sam , Bender Guido
Published: September 2023

The flow of reactants and biproducts to and from the anode in polymer electrolyte membrane (PEM) water electrolyzers is dictated by the properties of the porous transport layer (PTL). The PTL is made of titanium (Ti) fibers or sintered particles to provide stable thermal and electronic conduction pathways at the high overpotentials and acid conditions experienced at the anode. To prevent the formation of a thick native oxide on the Ti PTL surface, precious metal coatings are required. These coatings enable and maintain a reduced interfacial resistance between the PTL and catalyst layer. Understanding the impact of surface treatments and coatings on the morphology and composition of this interface is an important step to minimizing interfacial resistance, degradation and production costs. In this work, ion and electron beam techniques, including focused ion beam (FIB), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and scanning transmission electron microscopy (STEM), are used to investigate PTL coatings at the nanoscale.

A series of fiber-type PTLs with a range of platinum (Pt) coating thicknesses were synthesized using physical vapor deposition. The uniformity of the coatings was analyzed using SEM-EDS in both plan-view and cross-section. Sections of individual fibers were then removed using FIB lift-out technique and thinned to less than 50 nanometers for further analysis by STEM. The thickness and uniformity of the Pt coating was quantified from STEM images for each Pt loading and correlated with interfacial resistance measurements. Changes to the thickness and composition of the coatings and oxide layers after single cell tests will also be reported alongside additional insights from correlative characterization approaches like atomic force microscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. Overall, these findings will help steer the development of PTL treatments and coatings for highly durable and efficient PEM water electrolyzers towards meeting the U.S. Department of Energy’s Hydrogen Shot to reduce the cost of clean hydrogen production to $1 per kg by 2031.

Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.
In Situ Vs. Ex Situ Degradation Studies of IrO2-Based Porous Catalysts for Proton Exchange Membrane Water Electrolysis
Authors: Duran Silvia , Faustini Marco , Grimaud Alexis , Peron Jennifer
Published: September 2023

Regardless of the promising performances of Proton Exchange Membrane Water Electrolyzers (PEMWE) for H2 production, the high overpotential towards the oxygen evolution reaction (OER) (slow kinetic) still limits the large-scale use of such devices. 1,2

We have recently extended the aerosol synthesis route, a green, cheap and scalable synthesis technique, to the preparation of highly porous noble-metal pure and mixed oxides to optimize the electrocatalytic activity of the anode catalyst.2,3In this work, we are taking the advantage of the versatility of this process to prepare a large panel of iridium oxides with similar morphology and composition but different crystallinity and surface states and therefore different electrochemical properties.

By combining in situ (electrolyzer) and ex situ (three-electrode cell) electrochemical studies on these materials, this work aims at understanding the physico-chemical characteristics-stability relationships of iridium oxides as well as establishing a correlation between ex situ and in situ ageing experiments. Stress tests with different upper potentials limits are performed both in electrolyzer and RDE configurations to evaluate the stability of these materials, and the amount of iridium dissolved by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS). Beside chemical degradation, the unique morphology of these materials is particularly well-suited for following the morphological changes occurring upon ageing by Scanning Electron Microscopy (SEM).2,3 This study will help to improve the understanding of RDEs and PEMWEs testing behavior upon OER with the aim to correlate these two approaches using current metrics i.e., S-number 4, but also to elaborate or redesign efficient catalysts.

References

[1] A.S. Aricò et al.
J. Appl. Electrochem
., 2013. doi:10.1007/s10800-012-0490-5.

[2] M. Faustini et al.
Adv. Energy Mater
., 9 (2019), 1-11. doi :10.1002/aenm.201802136

[3] M. Elmaalouf et al.
Nat. Commun
., 12 (2021), 3935. doi : 10.1038/s41467-021-24181-x

[4] S. Geiger et al.
Nat. Catal
., 1 (2018), 508-515. doi: 10.1038/s41929-018-0085-6

Figure 1
(Invited) A Critical Review on the Expressions of Energy Efficiency Used in Low Temperature Water Electrolysis
Authors: Lamy Claude
Published: September 2023

The accurate knowledge of the energy efficiency coefficient of low temperature water electrolysis (Alkaline, PEM or AEM Electrolyzer) is a critical-point to estimate the total cost of electrolytic hydrogen production. After describing the fundamentals of these three processes and presenting the main data of water electro-dissociation under given temperature and pressure conditions, the energy efficiency coefficient can be calculated at the Laboratory scale by taking the ratio of the theoretical energy (ΔH) to decompose water under equilibrium conditions (no current) to the real energy used (ΔH + energy losses) to electrolyze water at a given current intensity. Different approximations of this coefficient are discussed and compared to data from literature. Conversely in the industry this coefficient can be calculated by taking the ratio of the total energy of hydrogen collected at the exhaust of the electrolyzer to the total energy (electricity + heat) supplied to the complete system. It is demonstrated that both definitions are consistent and similar if all the energy involved is taken into account. It is also shown that some approximations, in particular those neglecting the thermal energy in the denominator of this ratio, give efficiency coefficients larger than unity for cell voltages lower than the thermo-neutral voltage, which is a thermodynamic non-sense.

The next figure shows the plot of the theoretical energy efficiency coefficient ε

cell
for p = 1 bar under the STP conditions (U0
tn
= 1.48 V and U
0

rev
= 1.23 V) up to Ucell

= 2.0 V. There is a continuous decrease of ε

cell,th
vs. Ucell
from 1.0 to 0.85 when Ucell
= Utn
= 1.48 V under STP conditions.

Figure 1
Autonomous Materials Synthesis Strategies Towards Accelerated Discovery of Novel Functional Nanomaterials for Green Energy Production
Authors: Abdelhafiz Ali
Published: September 2023

Electrocatalysts designed by alloying two or more elements (e.g., transition metals) showed promising enhancement in catalytic activity and durability due to synergistic effects from alloying, such as strain engineering or electron exchange. The potential of the alloying approach is constrained by standard synthesis methods (e.g., wet chemistry and thermal decomposition techniques) due to the governing thermodynamics rules (e.g., miscibility of the different alloying elements). That renders the synthesis of high entropy alloys (HEA), with more than 3 elements, to be complicated and tedious to achieve by those conventional methods.

In the presented talk we are presenting different strategies to synthesize metastable high entropy alloys (HEA) and their outstanding catalytic performance towards OER, in correlation to their unique chemistries and structures. Rapid cycling of temperature from room 25 °C to highly elevated levels (1700 °C), in conjunction with ultra-rapid cooling, within milli-second range have been demonstrated by different methods including rapid Joule heating, Intense light flashing, and microwave plasma shock. Our results show successful synthesis of non-noble metals HEA NPs, possessing higher catalytic activity than IrO2 catalyst for OER. The nature of the alloying elements dictates OER activity by promoting different oxidation states of the catalytically active transition metals (e.g., Fe, Ni and Co). In addition, a phenomenal in-situ chemical welding of HEA NP to carbon support, yielded HEA catalysts with two orders of magnitude longer durability than IrO2. Our developed techniques resulted in formation of super-strong metal-carbide bonds “chemically welding” HEA NP to the catalyst support.

Synthesis of various HEA catalyst and their electrocatalytic performance screening has been carried out by using liquid handler robots and multi-axes robotic arm systems. Moreover, to optimize the design of materials (structure and chemistry), we are using active learning techniques to evaluate the achieved performance results by applying Gaussian process, followed by applying Bayesian Optimization techniques to propose novel chemistries and structures with a higher probability to achieve further improved performances. The presented the study does not open the door only towards developing novel catalysts for energy production. However, it presents a strategy with multiple successfully demonstrated platforms towards accelerated discovery of novel materials. The high-throughput nature of the synthesis protocols presented in this talk can produce tens of thousands of different novel chemistries, at the same time taken by conventional methods to synthesize just a few, at a minimal energy consumption, cost, and manpower.
(Invited) Carbon-6 Based Sustainable Value Chains Towards Specialties and (Aviation) Fuels Based on Low-Temperature PEM-Water Electrolysis and Syngas Fermentation
Authors: Schmid Guenter , Neubert Heinz , Lettenmeier Philipp , Haas Thomas
Published: September 2023

Sustainable value chains by coupling electrolysis and fermentation

The energy transition also needs a raw material transition. The process sequence of water electrolysis and syngas fermentation was found to provide access to C4-C6 based value chains based on CO2 and H2. In the German Kopernikus and Rheticus projects Siemens Energy Global GmbH & Co. KG (SE) and Evonik Operations GmbH focused on a sustainable synthesis of C6 oxygenates for specialty chemicals, food additives and even fuels1,2. Routes to kerosene exist. The technology was successfully implemented in chemical plant environment at Marl with an annual production capacity of ~15t. The scaling into the multimillion-ton annual production range depends on various boundary conditions, such as the availability of renewable energy at competitive cost, the political situation as well as its customer acceptance.

Silyzer 300 PEM electrolysis

SE is one of the key companies willing to implement the German National Hydrogen Strategy3 until 2030. The current product is named Silyzer 300® with 17,5 MW rated power at begin of life on system level4. The stack core consists of a non-pressurized array with 24 modules, producing around 335 kg of hydrogen per hour. SE is investing more than 60 Mio.€ for the massive ramp-up of electrolyzer production capacity through automation5. Series production (SEGIWA) and de-risking, qualification for large-scale application (= de-risking; DERIEL) are funded within the H2Giga program6.

Perspectives in AEM-Membranes

Anion Conducting Membranes offer design and operation options in polymer membrane water electrolysis. Electrochemical data from the project AEMready will be presented with respect to noble metal free catalysts and choices of membranes.

Acknowledgement

The investigations reported on the value chain was partly funded by the BMBF under the contract numbers Kopernikus I & II (FKZ: 03SFK2J0-2), Rheticus I & II (FKZ: 03SF0574B). Scaling is BMBF-supported by the H2Giga initiative within the projects SEGIWA (FKZ: 03HY121A) and DERIEL (FKZ: 03HY122A). AEM activities are funded by AEMready (FKZ:03SF0613B).

References

Haas, R. Krause, R. Weber, M. Demler, G. Schmid, Nature Catalysis, 2018, 1, 32–39.

https://www.bmbf.de/de/fuer-eine-klimafreundliche-industrie-kohlendioxid-und-wasserstoff-als-rohstoffe-fuer-12543.html .

https://www.bmwk.de/Redaktion/EN/Publikationen/Energie/the-national-hydrogen-strategy.pdf?__blob=publicationFile&v=6.

https://www.siemens-energy.com/global/en/offerings/renewable-energy/hydrogen-solutions.html?gclid=EAIaIQobChMIsuu-wMHV-wIVktZ3Ch24ngoYEAAYASAAEgJUF_D_BwE.

https://press.siemens-energy.com/global/en/pressrelease/new-production-facility-berlin-siemens-energy-wants-eliminate-worlds-most-potent .

https://www.wasserstoff-leitprojekte.de/projects/h2giga .
Advancements in Thin, Reinforced Proton Exchange Membranes for Water Electrolysis
Authors: Gebhardt Ryan , Wrubel Jacob A , Bartuska Samuel , Vander Woude Meghan , Wright Ben , Bender Guido , Park Andrew
Published: September 2023

Proton exchange membrane water electrolysis (PEMWE) is emerging as one of the most promising methods to produce clean hydrogen at industrial scale. New PEMWE stack designs require high voltage efficiency and differential pressure operation without sacrificing low hydrogen in oxygen concentrations in the anode stream. Membranes used in current stack designs, such as Chemours Nafion™ N115, are thick to provide strong mechanical stability. However, employing a thinner and mechanically supported membrane can enhance both the electrochemical performance and mechanical properties. With the demand for cheaper hydrogen, these new membrane designs are needed to achieve advanced performance metrics. In this presentation, recent improvements in membrane design at Chemours will be summarized.

Novel architectures comprise a thin, reinforced composite membrane approach, utilizing a lower equivalent weight (EW) polymer that can surpass the performance of the current commercial membranes. For example, overpotential is reduced by >150 mV at 3 A/cm2 for novel membranes compared to Nafion™ N115 at 80°C. However, one concern with having a thinner film is the increase in hydrogen crossover, since the lower explosive limit (LEL) for hydrogen in oxygen is only 4 vol %. PEMWE differential pressures of up to 30 bar on the cathode side can exacerbate these hydrogen crossover challenges. To mitigate this hazard, gas recombination catalyst (GRC) additives have been implemented within the membrane where the GRC recombines hydrogen and oxygen to form water. A reduction in anodic hydrogen in oxygen content of >50x has been observed, assuring the safe operation at high differential pressures for these thin membranes. Polarization curves across different membrane constructions were analyzed as well as hydrogen crossover for various GRC designs. Comparisons will be presented demonstrating the improved performance and reduced hydrogen crossover.

Figure 1