bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Topsoe’s Vision on the Commercialization of Solid Oxide Electrolysis Cells: Challenges and Accomplishments in Upscaling to the MW Scale
Authors: Sala Elena Marzia , Hauch Anne , Padinjarethil Aiswarya Krishnakumar , Blennow Peter Gustav , Perin Giovanni , Rass-Hansen Jeppe , Heiredal-Clausen Thomas , Holstebroe Majken , Fittkau Birkmose Malte Frederik , Mai Andreas , Sune Thyden Karl Tor , Ebbesen Sune Dalgaard , Hultqvist Michael , Moses Poul Georg
Published: December 2024

Topsoe is strongly committed to drive the decarbonization of the so-called hard-to-abate sectors, such as iron and steel manufacturing and long-haul transportation, by implementing the industrial scale production of sustainable fuels and chemicals via solid oxide electrolysis cells (SOECs).

To enable the upscaling of the SOEC technology at the pace required by the increasing green hydrogen demand and the company’s target of full climate neutrality by 2040, Topsoe is building a facility able to produce electrolysis stacks and modules with an annual capacity of 500 MW, equaling the production of 125,000 tonnes of hydrogen p.a. The construction of the production facility, covering an area of over 23,000 m2, was initiated at the end of 2022 in Herning, Denmark, and is progressing at an accelerated pace, aiming at full operation in 2025. The 2nd generation Topsoe Stack Platform (TSP-2) produced in the Herning facility consists of SOEC stacks designed for H2 production from the electrolysis of steam at pressurized conditions (>3 bar), while maintaining the ability to operate at ambient pressure to produce CO by CO2 electrolysis. The TSP-2 stack has a capacity of >15 Nm3 H2/h, to be further combined in a 12 stacks-core module totaling over 180 Nm3 H2/h.

Exciting and solid results have been recently released by Topsoe on the SOEC core’s first demonstration test at industrially relevant conditions [1]. The demo unit, consisting of 12 stacks (1200 cells) operating at a constant pressure of 3.5 bar and a combined stack power of 350 kW, showed remarkable stability over 2250 hours of operation (Figure 1). These impressive durability results were obtained at a core efficiency of approximately 93% (LHV of hydrogen), with an electricity consumption of the core of around 36 kWh/kg H2 and a ramp-up time to reach 100% of the load (approximately 230 A throughout each stack in the core) of just three minutes.

While providing an overview of the continuing demonstration tests ongoing at a stack and core level, this presentation will report the developments of the construction of the manufacturing facility in Herning, highlighting the major challenges and key factors playing a role in the large-scale commercialization of SOECs.

References:

[1] www.topsoe.com/blog/breakthrough-in-green-hydrogen-topsoes-soec-demo-reveals-strong-results. Last accessed on 18-04-2024.

Figure 1: Average cell voltage for all the 1200 cells in the 12 stacks of the Topsoe SOEC core’s demo unit as a function of time of operation.

Figure 1
(Invited) Ionic Nanoarchitectonics to Create Novel Functional and High-Performance Devices, Such As Neuromorphic Devices
Authors: Terabe Kazuya , Tsuchiya Takashi , Tsuruoka Tohru
Published: December 2024

Many semiconductor devices are used in electronic information equipment, which is indispensable in today's information society. Progress in memory and computing functions through the integration of semiconductor devices has been supported by the development of ultra-fine processing technology, but there are concerns that this progress will slow down in the near future. In order to continuously improve the performance of electronic information devices, it is therefore necessary not only to further develop conventional semiconductor devices, but also to create innovative devices that operate according to new principles.

Recent years have also seen the development of hardware-oriented artificial intelligence (AI) technologies, such as brain-inspired computers that operate with low power consumption and small size. To realize such hardware-oriented AI systems, it is necessary to create devices with various unique functions, such as neuromorphic devices that mimic the structure and functions of the brain. These devices would include not only conventional semiconductor devices with properties suitable for digital arithmetic processing, but also devices with properties suitable for analogue arithmetic processing based on new operating principles.

Material properties are strongly influenced by small rearrangements and substitutions of constituent atoms. We have vigorously explored interesting nanophenomena and new functions arising from the control of nano- to atomic-scale ultrafine structures, such as small changes in atomic arrangement using ion transport [1-3]. This control of ultrafine structure can be achieved using ionic nanoarchitectonics methods, which allow local control of ion transport and electrochemical reactions occurring at solid interfaces and surfaces (Fig. 1). We have exploited various nanophenomena generated by this method to create ionic devices with electrical, magnetic and optical functions. In this talk, we will present various ionic devices created using ionic nanoarchitectonics, such as artificial vision devices that mimic the human retina to reproduce optical illusions, and decision-making devices that learn and make decisions on their own. In addition, ionic devices produced by ionic nanoarchitecture show promise for the development of hardware-oriented AI technology, the next generation of electronic information technology.

References: [1] K. Terabe, T. Tsuchiya, T. Tsuruoka, “A variety of functional devices realized by ionic nanoarchitectonics, complementing electronic components”, Advanced Electronic Materials, 8 (2022) 2100645. [2] K. Terabe, T. Tsuchiya, T. Tsuruoka, “Solid state ionics for the development of artificial intelligence components, Japanese Journal of Applied Physics, 61(SM) (2022) SM0803. [3] K. Terabe, T. Tsuchiya, T. Tsuruoka, “Atomic scale switches based on solid state ionics”, Advances in Physics: X, 7 (2022) 2065217.

Figure 1
Optimization of Reservoir Computing Utilizing Interfered Spin Waves
Authors: Nishimura Maki , Namiki Wataru , Nishioka Daiki , Terabe Kazuya , Tsuchiya Takashi
Published: December 2024

Reservoir computing is a learning model that enables low-cost and fast learning compared to conventional deep learning. It enables physical implementation by replacing the reservoir part with a physical device that possesses nonlinearity, short-term memory, and high dimensionality. In particular, it was theoretically predicted that spin wave interference can perform highly efficient reservoir computing in micromagnetic simulations,[1] and it was experimentally verified by the present authors.[2] Whereas the computational performance was suggested to vary significantly depending on the interval of input voltage pulses used for spin wave excitation and the applied magnetic field intensity, the details were unclear to date. Therefore, we expanded the measurement range to investigate detailed mechanism of the system and to explore untouched high performance in the study.

We use a device fabricated on the surface of a single crystal, as shown in Fig. (a), then we performed one of the most important prediction benchmark tasks, the Nonlinear Autoregressive Moving Average (NARMA) model. Since it has been found that utilizing the nonlinear interference of spin waves through multi-detection demonstrates high performance, in this study, we utilized both Detection A and Detection B. We evaluated the prediction error of NARMA10, which requires short-term memory up to 10 steps, by varying the applied magnetic field and the interval of input voltage pulses under measurement conditions. As shown in Fig. (b), the comparison between the target waveform and the output waveform during training and testing under the conditions of a magnetic field of 182 mT and a pulse interval of 23.6 ns shows a good match, at that time, the error was 0.183 during the testing phase. Next, we examined the detailed condition dependence in NARMA10. As indicated in Fig. (c), high performance is obtained in the region where the pulse interval is between 20 and 30 ns, while the performance was low in the region below 19.3 ns, particularly in the strong magnetic field range from 188 mT to 200 mT. We will discuss the condition dependence with the other NARMA models like NARMA2. Additionally, we will discuss in detail the dependence on input pulse intervals, along with evaluations of short-term memory capacity and nonlinearity. This work was in part supported by Innovative Science and Technology Initiative for Security Grant Number JPJ004596, ATLA, Japan and JST PRESTO (JPMJPR23H4).

【Reference】[1] Nakane et al., IEEE Access
6, 4462 (2018).[2] Namiki et al., Adv. Intell. Syst.
5, 2300228 (2023).

Figure 1
Synthesis, Thermal Stability, and Proton Conductivity of Nam
1-X
Li1-X
H
x
(PO3)3·YH2o (M : Ni2+ and Mg2+)
Authors: Ishikawa Shota , Takahashi Haruya , Otsuka Keita , Ueta Naoya , Matsuda Yasuaki
Published: December 2024

Mixed-cation phosphates are attractive materials as proton electrolytes covering the intermediate temperature range [1,2}. Depending on the combination of constituent elements, these materials exhibit various crystal structures with thermally stable tunnel-shaped frameworks and chains of water molecules arranged along PO4 tetrahedral chains, which act as pathways for proton diffusion. Among them, NaMg1-xLixHx(PO3)3・yH2O exhibits proton conductivity over 10-2 Scm-1 in 150-500°C [1]. Since crystal water is arranged using PO4 tetrahedral chains as a template, clarifying the correlation between the PO4 chain arrangement and proton conductivy is important for material design of new proton conductive phosphates. NaM1-x
Li1-x
H
x
(PO3)3·yH2O (M: Mg2+ and Ni2+) provides a crystal structure with a completely different arrangement of PO4 tetrahedra chains due to the variation in the M cation. In this study, aiming to develop a new proton conductor, NaNi1-x
Li
x
H
x
(PO3)3·yH2O containing Ni2+ (0.69 Å ) with an ionic radius smaller than Mg2+ (0.72 Å) was synthesized. Its thermal stability and proton conductivity were investigated and compared with NaMg1-xLixHx(PO3)3・yH2O.

Figure 1 shows the powder X-ray diffraction patterns for NaNi1-x
Li
x
H
x
(PO3)3·yH2O. Similar diffraction patterns to NaNi(PO3)3 [3] were observed for all compositions within the range of x = 0 – 0.2, with no reflections indicating impurity phases. All observed reflections were attributed to the crystal structure with space group Pcca, confirming the formation of a single phase with the NaNi(PO3)3-type structure in the new composition. In the range of x = 0 - 0.20, the shrinkage of the lattice corresponding to the change in composition was observed, and the formation of the solid solution was confirmed. In FTIR spectra, enhancement of the O-H and P-O-H peaks with increasing x were observed, which suggests that the introduction of protons as a charge compensation of the replacement of Ni2+ to Li+. Proton conductivity of NaNi1-x
Li
x
H
x
(PO3)3·yH2O measured by AC impedance method showed positive tendency for the proton contents. In the Arrhenius plot of NaMg1-xLixHx(PO3)3・yH2O, a competing behaviour was observed in which the increase in proton conductivity due to temperature rise and the decrease in the conductivity due to the desorption of crystal water. The highest conductivity was obtained for the sample with x = 0.20 and the value over 10-3 Scm-1 at 300°C. Details of conductivity and thermal properties will be discussed.

References

[1] N. Ueda, et al, Mater. Adv.,2, 6603 (2021).[2] Y. Matsuda, et al., Dalton Trans.
50, 7678 (2021). [3] F. Erragh, et al, Acta Crystallographica, Section C :
Crystal Structure Communications, 54, 1746 (1998).

Acknowledgment

This research was partially supported by Kanto Branch of the Electrochemical Society of Japan, JGC Saneyoshi Scholarship Foundation, JSPS KAKENHI Grant Number 24K08584 and 21K05246.

Figure 1
Effect of SOEC Operating Conditions on the YSZ Electrolyte Conductivity
Authors: Toriumi Hajime , Bagarinao Katherine Develos , Kishimoto Haruo , Yamaguchi Toshiaki
Published: December 2024

Solid oxide electrolysis cells (SOECs) using the reverse reaction of solid oxide fuel cells (SOFCs) have attracted attention as green hydrogen production methods and H2O-CO2 co-electrolysis technologies. SOEC has an advantage of higher efficiency than other electrolysis technologies because it can utilize not only electrical energy but also thermal energy. Yttria-stabilized zirconia (YSZ) is often used for the electrolyte materials in SOECs. Generally, in fuel-electrode-supported SOECs utilizing YSZ electrolyte, the NiO-YSZ fuel electrode support and YSZ electrolyte are co-sintered at high temperatures in the range of 1300-1400 oC, so the NiO in the fuel electrode support inevitably diffuses into the YSZ electrolyte. It is known that the NiO dissolution into YSZ accelerates the YSZ conductivity degradation especially under reducing atmosphere, because the fast phase transformation from the cubic (higher conductivity) phase to the tetragonal (lower conductivity) one occurs via nickel reduction in the YSZ lattice [1,2]. Such conductivity degradation has already been well observed in YSZ bulk materials, but in the case of fuel-electrode-supported SOECs, the details of how the conductivity of the Ni-diffused YSZ electrolyte on the fuel-electrode support changes under the SOEC operating conditions are not clear.

In this work, in order to clarify the relationship between the conductivity changes of Ni-diffused YSZ electrolytes and SOEC operating conditions of the fuel-electrode-supported cells, we used the fuel-electrode-supported SOECs with Ni-diffused YSZ electrolytes via high temperature co-sintering process. The EIS data at 1.3 V are analyzed by fitting with an equivalent circuit to separate each resistance component. These results will be shown in this presentation.

This study is partly based on results obtained from a project, JPNP21022, commissioned by the New Energy and Industrial Technology Development Organization (NEDO).

References

[1] T. Shimonosono, et al., Solid State Ionics 225 (2012) 69-72.

[2] W.G. Coors, et al., Solid State Ionics 180 (2009) 246–251.
High Surface Proton Conductivity of Epitaxial CeO2-
δ Thin Film below Medium Temperature Range
Authors: Notake Go , Tani Minami , Yamada Mariko , Morizane Ryota , Tabuchi Riku , Higuchi Tohru
Published: December 2024

Fluorite-type oxide such as Yttria-stabilized zirconia (YSZ) or doped-CeO2-
δ ceramics are good electrolyte candidates for solid oxide fuel cells (SOFC) due to their high oxygen ion conductivity in high temperature range above 700 ºC[1]. Furthermore, porous and nanocrystalline CeO2-
δ exhibit proton conduction at the surface below 100 °C[2]. This surface proton conduction is believed to the Grotthuss mechanism caused by the adsorption of water molecules. Since protons are produced by adsorbed water molecules and conduct through the layer of adsorbed water, oxygen vacancies and lattice constant are important parameters to enhance proton conduction. If high surface proton conduction can realize in CeO2-
δ thin film, this may be more suitable than porous or nanocrystalline materials for new electrochemical devices and smart fuel cells.

Recently, our group reported that the higher ion conductivity depends on the lattice constant and grain size for YSZ and Sm-doped CeO2-
δ thin films[3,4]. However, the effect of crystallinity on the ion conductivity is not clarified. In this study, we have prepared the CeO2-
δ thin films on YSZ (002) substrates by RF magnetron sputtering and probed their surface proton conduction below 300 °C in terms of electrical conductivity and electronic structure.

The CeO2-
δ ceramics target was prepared by solid-state reaction method. The CeO2-
δ thin films with thicknesses of ~20 and ~120 nm were prepared by RF magnetron sputtering by adjust the deposition time. The sputtering conditions is followed; The base pressure was kept at 5.0×10-8 Torr and the deposition pressure was kept at 3.5 mTorr to control the Ar flow rate of ~2.67 sccm. The RF power was fixed at 30 W. The crystal and electrical structure of CeO2-
δ thin films were evaluated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (PES) and X-ray absorption spectroscopy (XAS). The electrical characteristics was evaluated by A.C. impedance method.

The prepared CeO2-
δ thin films on the YSZ substrates were due to the exhibited 200 and 400 peaks. Figure shows the Arrhenius plot of the conductivity of the as-deposited and wet-annealed CeO2-
δ thin films, indicating thermally activated behavior in the medium temperature range but different behavior below 100 °C. The conducting carrier in the medium and room temperature range is considered to be oxide ion and proton, respectively. In this poster, we will show that the surface proton conduction of CeO2-
δ thin film is closely related to the lattice distortion and oxygen vacancies concentration at the surface.

References

[1] Eguchi, et. al., Solid State Ion.
52, 165, (1992).

[2] Shirpour, et al., Phys. Chem. Chem. Phys.
13, 937, (2011).

[3] Takayanagi, et. al., Solid State Ion.
311, 46, (2017).

[4] Nishioka, et. al., Nanoscale Res. Lett.
15, 42, (2020).

Figure 1
Micro-Scale Thermal Partial Oxidation Reforming of Liquid Fuels and Solid Oxide Fuel Cell Performance and Stability Analysis
Authors: Demers Guthrie , Rukmini Adrija , Milcarek Ryan J
Published: December 2024

Thermal partial oxidation of hydrocarbons to hydrogen and carbon monoxide (i.e., synthesis gas) is limited for conventional scale reactors due to soot formation under higher fuel/air equivalence ratios. Recent research into micro-scale (<4 mm diameter) thermal partial oxidation reactors with a controlled temperature of 800-900 °C has shown promise for conversion to synthesis gas without soot formation. Direct integration of Solid Oxide Fuel Cells (SOFCs) with these micro-scale thermal partial oxidation reactors has been proposed for portable power generation systems. In this work, the micro-scale thermal partial oxidation of methanol/air is investigated at fuel/air equivalence ratios from 1-5 and at a temperature of 800 °C. High conversion rates to synthesis gas are measured with a gas chromatograph for equivalence ratios between 1.5 and 3, with the concentration of hydrogen exceeding 10% and approaching chemical equilibrium predictions. A micro-tubular SOFC is integrated with the micro-scale thermal partial oxidation reformer to electrochemically oxidize the synthesis gas while generating power. SOFC polarization losses are investigated at different equivalence ratios and temperatures of the reformer with results indicating the mass transport losses decrease significantly as the equivalence ratio increases. Peak power densities occur when the synthesis gas concentration is maximized. Short term testing of the SOFC is stable no carbon deposition on the Ni-YSZ anode.
Accelerating Discovery of Spinel Oxides for Bifunctional Oxygen Electrocatalysts
Authors: Jeong Incheol , Shim Yoonsu , Yuk jong Min , Roh Kimin , Lee Chan-Woo , Lee Kang Taek
Published: December 2024

The increasing demand for sustainable energy has prompted extensive investigations into electrochemical conversion devices such as fuel cells, water splitting systems, and metal-air batteries. The efficiency of bifunctional oxygen electrodes plays a crucial role in overall electrochemical performance. In recent times, spinel oxides (AB2O4) have emerged as promising candidates for this purpose; however, the limited prior research emphasizes the necessity for a thorough and exhaustive exploration. This study introduces a computational framework that combines machine learning techniques with density functional theory calculations to systematically screen 1240 spinel oxides. Stability evaluations are guided by geometric relation and crystal-likeness score. A metal/nonmetal classifier based on transfer learning is utilized to address data scarcity, thereby improving prediction accuracy. Several selected candidates exhibit superior performance compared to the benchmarking perovskite oxide. Furthermore, we emphasize their potential as mixed ionic and electronic conductors, featuring a network of ion diffusion pathways. This research establishes design principles for the development of high-performance spinel oxide bifunctional oxygen electrocatalysts.
Preparation of Y2O3-Stabilized ZrO2 Film By Warm Isostatic Press (WIP) Method for Metal-Support Solid Oxide Fuel Cells (SOFCs)
Authors: Nakagawa Niki , Song Jun Tae , Watanabe Motonori , Inada Miki , Ishihara Tatsumi
Published: December 2024

Solid Oxide Fuel Cells (SOFCs) are attracting as highly efficient power generator and almost no air pollutant emitted. So, SOFCs are now practically used, however, current SOFCs are consisted of all ceramics and so reliability and cost are the issues. Metal support SOFC (MS-SOFCs) is used porous metal for substrate and so high mechanical strength and also easy gas sealing is expected. However, preparation of dense electrolyte film on porous metal substrate is now the most significant issue to solve. In this study, we proposed oxide dense plate of NiO-NiFe2O4 as precursor of MS-SOFCs and after deposition of dense electrolyte film, dense oxide disc of NiO-NiFe2O4 is changed to porous Ni-Fe porous support by reduction in H2 stream[1]. For making thin film of Y2O3 stabilized ZrO2(YSZ), warm isostatic press (WIP) was used by using YSZ tape prepared by tape casting method.

Commercial YSZ powder (TOSOH TZ8Y) was used after ball mill treatment and after making slurry, YSZ green sheet was obtained by tape casting of YSZ slurry on plastic film and then the obtained YSZ film was transcribed onto NiO-NiFe2O4 substrate with warm isostatic press (WIP) at 353K. After co-sintered at 1473K for 6 h, dense YSZ film with 10mm was obtained followed by reaction in H2 stream at 973K. Sm0.5Sr0.5CoO3 was used as cathode. After reduction, change in size and porosity of NiO-NiFe2O4 were less than 6% and 39%, respectively.

Figure 1 shows power generation property of the obtained Ni-Fe supported YSZ cell at 973 K. The open circuit potential was closed to the theoretical value of 1.03 V and reasonable power density of 340mW/cm2 was achieved at 973K. Slightly lower OCV may be results of Fe diffusion into YSZ cell and so, functional inter layer to prevent elemental diffusion was also investigated in this study. This study reveals that metal support YSZ can be obtained by WIP method.

Acknowledgement; This study was financially supported by New Energy and Industrial Technology Development Organization (NEDO,JPNP20003), Japan

Ju, Y‐W., S. Ida, and T. Ishihara. Fuel Cells6 (2012): 1064-1069.

Figure 1 Power generation curves of metal support SOFC using YSZ film prepared with WIP method.

Figure 1
Highly Bendable Solid Oxide Fuel Cells Via Phase Control of Zirconia-Based Electrolyte
Authors: Won Bo-Ram , Kim Yo Han , Jeong Hyeongwon , Park Dayoung , Myung Jae-Ha
Published: December 2024

Despite numerous studies, conventional solid oxide fuel cells (SOFCs) face limitations in commercialization due to the vulnerability of brittle ceramic materials to external stress. To address this issue, we propose a structural approach to design the support with excellent energy absorption capability using a flexible ceramic. In this study, we introduce a next-generation concept of highly flexible SOFCs with a bendable zirconia-based electrolyte, aiming to enhance mechanical stability and ensure long-term operation. The mechanical flexibility of the electrolytes is achieved by controlling the crystal structure within the range corresponding to a transformable tetragonal phase (with a tetragonality range of c/a > 1.010). Furthermore, we adjust the mechanical strength and ionic conductivity by varying the tetragonal phase fraction depending on sintering temperatures. Finally, the optimized electrolyte demonstrates superior bending strength and ohmic resistance properties, enabling it to withstand severe deformations such as folding. Based on experimental results, we have successfully fabricated an ultra-thin and highly flexible SOFC (with a total thickness < 55μm) using simple methods including tape-casting and screen-printing. Our approach achieves the highest cell performance among reported flexible SOFCs, showcasing significant potential for advancing SOFC technologies. With the advantages of being lightweight and low in volume, our innovation opens up a wide array of applications in mobile devices, without the risk of thermomechanical fracture.
From Mechanism Study to Catalyst Design: Exsolved Ru Nanocatalysts on Proton Conducitng Oxide for Efficient Ammonia Synthesis
Authors: JI HO-IL , Kim Joonhwan , Kim Hayoung , Yang Sungeun
Published: December 2024

Since it was revealed that the ammonia synthesis reaction is associated with the nitrogen adsorption energy, represented by a volcano plot, the catalysts placed near the peak of volcano plot, particularly ruthenium (Ru), have been actively investigated. For high efficiency of ammonia synthesis under mild conditions, the requirements of supported Ru catalysts are i) electron donating ability of supports (as promoters) that weakens the N≡N bond, ii) hydrogen absorption/desorption capability of supports to suppress H2 poisoning on Ru surface, iii) refractory property for maintaining high specific surface area of supports, and iv) the structurally robust and uniformly distributed Ru nanoparticles. However, the supported Ru catalyst that simultaneously fulfills all requirements above has yet been developed. Here we report a highly active exsolved Ru nanocatalyst supported on perovskite proton conducting oxide, BaCe0.55Zr0.3Y0.15O3-δ (BCZY), for ammonia synthesis at atmospheric pressure based on the understanding of exsolution mechanism.

The supported catalyst, 5mol% Ru-added BCZY, BaCe0.5Zr0.3Y0.15Ru0.05O3-δ, was synthesized via solid state reaction using appropriate amount of oxide precursors. Analyses of XRD for crystal structure, TEM for microstructure observation, TGA for measurement of mass change against temperature, XPS for determination of oxidation state, BET for surface area measurement, and catalytic activity for quantifying ammonia synthesis rate were carried out.

The exsolution is basically driven by reduction of oxide support, corresponding to the mass loss owing to the oxygen release. Thus, the decrease in mass directly associated with the Ru exsolution in a form of metal. Based on in situ TG profile at 1000oC under reducing atmosphere, it was verified that the Ru exsolution process is controlled by size-related strain, and the degree of exsolution can be effectively enhanced as the reduction time increases, e.g., from 1h to 20h. The exsolved Ru nanoparticles on proton-conducting oxide support formed by 20h reduction treatment at 1000oC had diameter of ~6 nm, and exhibited higher catalytic activity for ammonia synthesis reaction compared to exsolved Ru via 1h reduction treatment as well as the previously reported catalysts. The use of proton conducting oxide support, which has electron donating capability, structurally refractory property, and hydrogen absorption/desoprtion capability, could possibly be synergistic to boost the catalytic activity of exsolved Ru nanocatalyst. In this presentation, the details on exsolved Ru catalyst as a function of temperature, probable exsolution mechanism, and role of proton conducting oxide support will be further discussed.
Compact and Portable Desalination Using Architected Silver Sponge Electrodes
Authors: Neale Zachary G. , DeBlock Ryan H. , Rolison Debra R. , Long Jeffrey W.
Published: December 2024

Freshwater, a resource critical to social and economic stability, can become temporarily inaccessible after natural disasters such as earthquakes and hurricanes. Transport of water to remote areas during emergencies is expensive and potentially dangerous. Production of fresh water from local brackish and saline resources requires compact, mobile and energy-efficient devices. Reverse-osmosis (RO) uses high-pressure pumps that make down-sizing to mobile scales challenging, while an alternative to RO, capacitive deionization (CDI) based on low-density, low-capacity carbon electrodes, necessitates large footprint devices that are better suited for stationary desalination. Faradaic deionization (FDI) based on the silver–silver chloride conversion reaction provides high-capacity desalination in smaller formfactors. The silver electrode, with a theoretical capacity of 238 mAh/g, is used to remove chloride ions but the low-dimensional architectures of sheet and mesh electrodes limit material utilization. We have developed architected silver and silver chloride sponges that demonstrate high salt removal capacity (80 mg/g, 68 mg/cm2) owing to their high-surface area porous structure. The three-dimensionally interconnected silver network facilitates electronic and ionic transport throughout the bulk of the sponge, enabling scaling to millimeters-thick electrodes. We investigate the design of compact multi-channel flow-cell devices using Ag/AgCl sponges toward practical desalination of brackish and saline waters.
Advancing Towards Energy Self-Sufficiency in Guam and Micronesia through the Development of Workers for the Blue Economy
Authors: Limtiaco John , Lopez-Ruiz Juan
Published: December 2024

Seawater and the oceans are the most abundant sources of water on Earth and represent a major reservoir for the production of electrolytic molecular hydrogen (H2), which is the critical clean energy carrier necessary for achieving sustainable social development. However, the high salt content and presence of organic matter in seawater interfere via the water (H2O) electrolysis reaction (2H2O →O2 + 2H2); thus, complicates the direct utilization of seawater. This challenge is particularly relevant for islands in Micronesia, where their remote locations and accessibility to seawater make the delocalized production of H2 and other possible energy carriers a promising strategy for energy independence and regional self-sufficiency.

Driving this strategy, the University of Guam (UOG) has partnered with Pacific Northwest National Laboratory (PNNL) to upskill UOG faculty and students on the use of electrochemical equipment through activities aimed at building the foundation for fundamental research in carbon neutral H2 generation. The activities focus on developing an understanding of the reaction complexity of the electrode/liquid interface with the goal of controlling reaction pathways for the electrochemical production of H2 via the hydrogen evolution reaction (HER: 4H+ + 4e- →2 H2) at the cathode and molecular oxygen (O2) via the oxygen evolution reaction (OER: 2H2O →O2 + 4H+ + 4e-) at the anode during the electrolysis of seawater. A fundamental understanding of the reaction mechanisms, kinetics, and influence of the complex environments and the simultaneous transformations that are occurring during the HER and OER is necessary in the realization of technologies that efficiently perform direct seawater electrolysis, while avoiding the pretreatments required for current electrolyzer technologies.

This collaboration represents an important partnership between the island of Guam and broader Micronesia and PNNL to train future workers for the Blue Economy. In addition to training future workers for the Blue Economy, the partnership is laying the foundation for UOG to become a major clean energy research center in Micronesia, providing the facilities and expertise to engage researchers in the region. The Micronesian region in the Western Pacific Ocean is a vast and culturally diverse region that includes four main archipelagos comprising of over six hundred islands encompassing 6.7 million square kilometers. The four main island groups in Micronesia include the Caroline Islands, Gilbert Islands, Mariana Islands, and the Marshall Islands. The University of Guam is the only four-year post-secondary educational institution located in Micronesia and establishing itself as the flagship research and partnership institution for all of Micronesia.
In-Situ Integration of Co-Active Sites in MnO@C Composite for Zinc-Air Battery Driven Water Splitting
Authors: Janani Gnanaprakasam , Lee Dong-Kyu , Surendran Subramani , Sim Uk
Published: December 2024

Multifunctional electrocatalyst-enabled electrochemical hydrogen evolution, oxygen evolution, and reduction reactions play pivotal roles in various energy conversion and storage devices and their integrated systems. The most difficult challenge in developing multifunctional electrocatalysts is effectively incorporating multiple active sites into one material. Herein, we have crafted the Co-MnO@C through the in-situ integration of elemental cobalt on manganese oxide@ carbon in a hydrothermal process and studied the critical role of elemental Co in a zinc-air-driven water splitting system. The Co-MnO@C was prepared on raising the temperature till 1000C in tube furnace and achieved the unique corona-like morphology that allowed the uniform distribution of the elemental Co on the MnO microstructures. The Lewis acidic and Lewis basic active sites, Co and MnO being the electrocatalytically active centers, initiate the activity. The designed heterostructure modulates the electronic structure and improves the conductivity by incorporating carbon in the structure. The crystal structure, composition, and morphology were inspected as a function of the electrocatalytic activity. Benefitting from the integrated effects of all the above factors, Co-MnO@C was successfully demonstrated in the zinc-air battery-powered electrochemical water splitting. Thus, this work offers a novel approach to designing multifunctional electrocatalysts and exploring their efficiency in integrated green energy devices.

Figure 1
Manufacturing of Proton Conducting Solid-Oxide Electrolysis Cells Based on Yttrium‐Doped Barium Zirconate Electrolyte
Authors: Ding Hanping , Zheng Shuanglin , Karki Saroj , Le Allison
Published: December 2024

Proton-conducting solid oxide electrolysis cell (P-SOEC) has been recently recognized as a promising technology for delivering fast hydrogen production at lower temperature range to hold the promise of utilizing cheaper stack materials and reducing degradation. The current P-SOEC technology has been progressed into a new development stage with promising technical accomplishments. The operating temperatures have been effectively pushed down to 500~600°C to enable use of cheaper interconnects and to improve material system compatibility. However, the P-SOEC development is in its early stage due to low technology readiness level limited by several technical issues lying in material system, thermal processing, and efficiency. Based on comprehensive considerations on efficiency and durability, BaZr0.8Y0.2O3 (BZY) is considered as stable electrolyte candidate for electrolysis operation under extremely high steam concentration. However, the manufacturing of BZY electrolyte in half cells is challenging due to the refractory nature on sintering. In this work, we demonstrate the recent efforts in manufacturing BZY based P-SOEC for achieving the dense electrolyte with less sacrifice in proton conductivity. Several approaches are utilized and compared for validating the sintering activity and resulted properties. This work paves a solid foundation for our further investigation on electrolysis behaviors to meet the requirements on performances and durability.
Pulse Oxidation to Mitigate Carbon Monoxide Poisoning in Electrochemical Hydrogen Pumps
Authors: Sharma Kritika , Ashoka Sahadevan Suchithra , Ramani Vijay K
Published: December 2024

Electrochemical hydrogen pumps (EHP) play a pivotal role in developing clean and sustainable energy systems, with applications ranging from hydrogen transportation to stationary power generation. However, the presence of carbon monoxide (CO) in the hydrogen stream can pose a significant challenge, leading to catalyst poisoning and decreased pump efficiency. This work introduces a novel and effective strategy to mitigate carbon monoxide poisoning in EHPs using pulse oxidation. Pulse oxidation involves periodically applying a positive increase in current to the electrode surface to create an anode overpotential that oxidizes CO from the catalyst surface. This technique offers a dynamic and precise means of selectively removing CO impurities from the hydrogen stream. Tailoring the current pulses to the specific electrochemical characteristics of CO can achieve targeted removal without compromising the overall pump performance. The study explores the influence of CO gas feed rate, pulse width, operating current, and pulse interval on EHP performance. Results show that optimizing these parameters significantly impacts separation efficiency, energy efficiency, and power consumption. This strategy promises to improve the reliability and longevity of EHPs in real-world applications. By effectively addressing carbon monoxide poisoning, pulse voltammetry opens new avenues for developing robust and efficient hydrogen pumping systems, contributing to the broader goal of establishing hydrogen as a clean energy carrier in a sustainable future.
First-Principles Investigation of the Optical Transition Energies of Cr3+ Impurity Ion
Authors: Subhoni Kurboniyon Mekhrdod
Published: December 2024

First-principles Investigation of the Optical Transition Energies of Cr3+ Impurity Ion

Cr3+ - transition metal ion impurity in crystals have been extensively studied for numerous technological application such as in medical diagnostics, food analysis, horticultural lighting, night vision, etc. [1]. Together with experimental studies, theoretical investigation is also a prerequisite for gaining a better insight into their optical properties and interpreting the available experimental information to develop an efficient Cr3+-doped phosphors, and thereby improving their potential for application.

In this talk, we will discuss about the evaluation of the optical transition energies of Cr3+ impurity ionin garnets systems using first-principles calculations in the framework a DFT by employing different kinds of the exchange-correlation functionals in order to test their ability to reproduce geometrical and electronic structures. We found that absolute values of the calculated optical transitions are not correct by analyzing electronic density of states (DOS) diagram approach, which overestimates the optical transition energies even with wrongly estimated trend. Furthermore, we presented the excited-state calculation with appropriately constraining the electron occupation for obtaining the equilibrium geometric structures of the ground and excited states. The opportunity excited state calculation method within DFT that can bring accurate information on structural properties of the ground state and the excited states, consequently, optical transitions for Cr3+ impurity will be pointed out.

Reference

T. Basore, W.G. Xiao, X.F. Liu, J.H. Wu, J.R. Qiu. Broadband near-infrared garnet phosphors with near-unity internal quantum efficiency, Adv. Opt. Mater. 8 (2020) 2000296.
Enhancing Efficiency in Perovskite Light-Emitting Diodes through Molecule-Induced Defect Passivation
Authors: Park Jin Kyoung , Heo Jin Hyuck , Im Sang Hyuk
Published: December 2024

Perovskites are gaining attention as next-generation materials across various fields due to their exceptional physical, electrical, and optical properties. Perovskite light-emitting diodes (PeLEDs), in particular, have achieved external quantum efficiencies (EQE) exceeding 30% with ongoing enhancements. However, inorganic PeLEDs, despite their durability, face efficiency challenges compared to their organic counterparts. This is primarily due to energy level misalignment and defects at interfaces or surfaces adjacent to the perovskite emitting layer and charge transport layers. Addressing these challenges, our research focuses on defect passivation as a key strategy for improving efficiency. We demonstrate significant efficiency enhancements in inorganic PeLEDs through the targeted introduction of organic molecules to passivate defects at the perovskite/hole transporting layer (HTL) interface and the emitting layer's surface, providing a promising avenue for advancing the field.
Photosynthesis of NH3 from NO3
– Using CH4 as a Reductant by a Homogenous Re Catalyst
Authors: Matsumoto Takahiro
Published: December 2024

In the early 20th century, the Haber-Bosch process emerged as a means to artificially synthesize NH3 from N2. Once converted to NH3, it becomes readily transformable into other reactive nitrogen (Nr) compounds, proving instrumental to humanity as a chemical fertilizer and industrial feedstock. However, recent assessments concerning “planetary boundaries” have underscored the substantial release of Nr into the environment, precipitating environmental challenges such as global warming, air pollution, water contamination, eutrophication, and biodiversity depletion (W. Steffen, K. Richardson, J. Rockström, S. E. Cornell, I. Fetzer, E. M. Bennett, R. Biggs, S. R. Carpenter, W. de Vries, C. A. de Wit, C. Folke, D. Gerten, J. Heinke, G. M. Mace, L. M. Persson, V. Ramanathan, B. Reyers, S. Sörlin, Science 2015, 347, 1259855). As consciousness surrounding carbon neutrality burgeons, the imperative to address nitrogen neutrality also emerges as a pressing concern. When (NH4)2SO4 is administered as a fertilizer, it undergoes conversion into NO3
–, a form of Nr, facilitated by soil microorganisms. This NO3
– infiltrates groundwater and courses into the ocean via river systems, engendering pollution at various points along its trajectory. Presently, the predominant approach for NO3
– remediation entails microbial conversion of NO3
– into N2, employing a hydrogen donor as a reductive agent. However, this method generates N2 from NO3
– using a hydrogen donor, thereby perpetuating the need for NH3 synthesized via the energy-intensive Haber-Bosch process. Hence, a preferable alternative involves the conversion of NO3
– into NH3 for subsequent reuse.

In this study, we present the transformation of NO3
– into NH3 utilizing CH4, a reductive agent obtainable from renewable sources, and light, a sustainable energy source, catalyzed by an organorhenium complex (T. Matsumoto, G. Nakamura, Japanese Patent 2022-110214). CH4 can be derived from livestock waste via CH4 fermentation, with the production of CH4 from renewable sources already established as a practical technology in many parts of the world, primarily harnessed for CH4-based power generation (R. Singh, P. K. Mishra, N. Srivastava, A. Shrivastav and K. R. Srivastava, in Bioenergy Research: Evaluating Strategies for Commercialization and Sustainability, ed., N. Srivastava and M. Srivastava, Wiley-VCH, Weinheim, 2021, pp. 245–254).
Single-Cell Analysis of Immune Synapse Formation Associated with Melanoma-T Cell Contact
Authors: Tamura Asuka , Katayama Noa , Saito Mikako
Published: December 2024

Extracellular vesicles (EVs) derived from an anaplastic mouse melanoma cell line made by Nanog overexpression of F10 (Nanog
+F10 cells) suppressed the metastasis of Nanog
+F10 cells. We suspected the involvement of immune cell system and focused on the cytotoxic activity of T cells. T cells are reported to form immune synapses when they come into contact with cancer cells and promote the introduction of cell-killing factors into cancer cells from the sites near immune synapses. However, the dynamic process of formation and loss of immune synapses is still unclear. Especially it is thought to differ depending on the type and the stage of cancer. Therefore, we believe that it is important to analyze the dynamic behavior of immune synapses in order to elucidate their possible role in the metastasis suppression mechanism of Nanog
+F10-EVs. In this study, a cytotoxic T cell line (CTLL-2) was used as a T cell model. The purpose of this study was to perform microscopic fluorescence analysis of immune synapses that are expected to be generated when CTLL-2 cells are loaded with Nanog
+F10-EVs and then co-cultured with Nanog
+F10 cells. We focused on PKCθ, one of the proteins constituting immunological synapses. First, Nanog
+F10-EVs were extracted from Nanog
+F10 cells by ultracentrifugation. The Nanog
+F10-EVs or PBS was added to CTLL-2 cells and cultured overnight. Then, Nanog
+F10 cells were co-cultured with the previously treated CTLL-2 cells on poly-L-lysine-coated glass slides. Cells were then fixed in 4% PFA/PBS, permeabilized with 0.1% Triton X-100, and blocked with 3% BSA/PBS. Immunostaining was then performed with drops of PE-labeled PKCθ antibody and Alexa Fluor® 647-labeled Nanog antibody prepared in 1.5% BSA/PBS to a concentration of 10 µg/mL. Observations were made using a confocal microscope LSM510 to observe the contact between CTLL-2 cells and Nanog
+F10 cells. The results showed that PKCθ was localized at the plasma membrane in Nanog
+F10 cells as expected, but its expression was weak in CTLL-2 cells. When multiple cells formed clusters, the localization was even more pronounced along the cell-cell contact surfaces, with areas of elevated PKCθ expression found on the Nanog
+F10 cell side at sites where CTLL-2 cells were likely in contact. On the other hand, in the case of Nanog
+F10-EVs loaded CTLL-2 cells, the observed fluorescence intensity suggests that the expression of PKCθ in CTLL-2 cells increased. Furthermore, the expression of PKCθ tended to increase when CTLL-2 cells and Nanog
+F10 cells were co-cultured for longer periods of time. It was found that the cytotoxic activity of CTLL-2 cells may be related to this increased expression of PKCθ.
(Invited) Gyroid 3D Network in Si@SiOx/C Nanoarchitecture for Lithium Ion Battery
Authors: Kim Jung Ho
Published: December 2024

Silicon-based materials are the most promising candidates to surpass the capacity limitation of conventional graphite anode for lithium ion batteries. Unfortunately, Si-based materials suffer from poor cycling performance and dimensional instability induced by the large volume changes during cycling. To resolve such problems, nanostructured silicon-based materials with delicately controlled microstructure and interfaces have been intensively investigated. Nevertheless, they still face problems related to their high synthetic cost and their limited electrochemical properties and thermal stability. To overcome these drawbacks, we demonstrate the strategic design and synthesis of a gyroid three-dimensional network in a Si@SiO
x
/C nanoarchitecture (3D-Si@SiO
x
/C) with synergetic interaction between the computational prediction and the synthetic optimization. This 3D-Si@SiO
x
/C exhibits not only excellent electrochemical performance due to its structural stability and superior ion/electron transport but also enhanced thermal stability due to the presence of carbon, which was formed by a cost-effective one-pot synthetic route. We believe that our rationally designed 3D-Si@SiO
x
/C will lead to the development of anode materials for the next-generation lithium ion batteries.
(Invited) Co-Precipitation of Ncm Precursor Using Taylor-Couette Reactor and Scale up Approaches for Mass Production
Authors: Song Jung Hoon
Published: December 2024

NCM cathode materials are now recognized as a promising candidate for EV application. The particle shape and surface morphology is very important factor to obtain a high density electrode. In addition, high speed production is needed to reduce the cell manufacturing cost. In this study, we developed NCM precursors using Taylor-Couette reactor system. It showed high throughput and good particle shape compared to conventional co-precipitation method. And also, good electrochemical performances were obtained.