bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of B-Site Doped Barium Niobate Perovskite Anodes for the Electrochemical Oxidative Coupling of Methane
Authors: Denoyer Luke H , Ramaiyan Kannan , Benavidez Angelica , Brearley Adrian , Garzon Fernando H. 
Published: December 2024

More efficient usage of shale gas reserves and natural gas resources will allow for higher olefin yields and lower greenhouse gas emissions. The oxidative coupling of methane (OCM) is a direct pathway for converting methane to ethylene at temperatures >700 °C. OCM catalysts preferably avoid COx products and limit coke formation on the catalyst. Often, catalysts are analyzed via computationally expensive DFT computations in combination with experimental results leading to long lead times for catalyst development. Perovskite oxide catalysts are useful for OCM due to their flexible bond networks and varied properties (conductivity, selectivity, surface area) based on synthesis/doping. This work aims to illustrate the utility of the bond-valence bond-length model (ionic model)1
,2 in conjunction with gas reduction experiments for rapid structure evaluation of the co-doped perovskite BaMg0.33Nb0.67-xFexO3-δ (BMNF, x=0.17,0.25,0.33). This perovskite catalyst has previously been adopted as a CO2 sensing material3 and an active/stable anode for the electrochemical oxidative coupling of methane4 (E-OCM). Further evaluation of this perovskite by our group illustrated the unique stability of ionic Fe into the BMNF while performing the oxidative coupling of methane5. This work delves into the crystal structure of the BMNF material as well as its chemical stability validated using a much more facile computational methodology featuring the bond-valence bond-length method. XPS, XRD, and reduction/oxidation high temperature cycling are utilized in conjunction to illustrate the stabilizing mechanisms for cations within the BMNF perovskite when exposed to highly reducing environments.

References

(1) Pauling, L. "The principles determining the structure of complex ionic crystals."
J. Am. Chem. Soc. 1929, 51 1010-1026.
(2) Lufaso, M. W.; Woodward, P. M. Prediction of the Crystal Structures of Perovskites Using the Software Program SPuDS. Acta Crystallogr. B
2001, 57 (6), 725–738. https://doi.org/10.1107/S0108768101015282.
(3) Kannan, R.; Mulmi, S.; Thangadurai, V. Synthesis and Characterization of Perovskite-Type BaMg0.33Nb0.67−xFexO3−δ for Potential High Temperature CO2 Sensors Application. J. Mater. Chem. A
2013, 1 (23), 6874–6879. https://doi.org/10.1039/C3TA10572E.
(4) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Ramaiyan, K. P. Highly Stable Doped Barium Niobate Based Electrocatalysts for Effective Electrochemical Coupling of Methane to Ethylene. Adv. Mater. Interfaces
2022, 9 (27), 2200796. https://doi.org/10.1002/admi.202200796.
(5) Denoyer, L. H.; Benavidez, A.; Garzon, F. H.; Electrochemical oxidative coupling of methane: deciphering the exceptional properties of BaMg0.33Nb0.67-xFexO3-δ for enhanced electrocatalysis and durable operation. Accepted by Energy & Fuels Feb.

2024
Development of Barium-Modified Anodes for Anode-Supported Solid Oxide Fuel Cells Fueled with Ammonia
Authors: Fujita Akinari , Muroyama Hiroki , Matsui Toshiaki 
Published: December 2024

Solid oxide fuel cells (SOFCs) have attracted significant attention due to their high power generation efficiency and low pollutant emissions. Owing to the use of solid oxide electrolytes, SOFCs are usually operated at high temperatures of 600–800 oC, leading to favorable fuel flexibility. Although alternative fuels such as hydrocarbon fuels are superior to pure hydrogen in terms of storage, transportation, and energy density, by-products from the fuels, as exemplified by carbon, will deteriorate the performance and stability of anodes.
Ammonia is promising as a carbon-free fuel for SOFCs because of its low cost, high hydrogen content and volumetric energy density, and ease in liquefaction and transportation under mild conditions. In ammonia-fueled SOFCs, the following reactions occur on the anode.
2NH3 → N2 + 3H2 (1)
H2 + O2− → H2O + 2e− (2)
Ammonia is decomposed to form nitrogen and hydrogen (1) and then the produced hydrogen is electrochemically oxidized (2). Thus, the anode material has to be active for ammonia decomposition as well as electrochemical hydrogen oxidation. The conventional Ni–YSZ electrode, however, is known to have low activity for ammonia decomposition. Therefore, it is necessary to enhance the catalytic activity of Ni–YSZ-based anode.
It has been reported that the addition of basic components to Ni-based catalysts improve the ammonia decomposition activity. In this study, then, we modified the anode of a commercial anode-supported SOFC button cell (Elcogen, ASC–400B) with barium components by dropping a solution containing barium salts onto the electrode. The effect of additive component on the cell performance was evaluated.
An aqueous solution of 2.0 M Ba(CH3COO)2–0.7 M C2H5NO2 was dropped onto the anode of anode-supported cell, followed by the heat-treatment at 800 oC for 2 h. This series of process was repeated several times so that desired amounts of barium component were loaded. Performances of the as-received cell and the fabricated cells were evaluated under hydrogen- and ammonia-containing fuels at 600–750 oC. For the as-received cell, cell performances were comparable in both fuels at 700 oC, indicating that the ammonia decomposition proceeded over the anode, while the performance were much different between H2 fuel and NH3 fuel at lower temperatures. On the other hand, comparable performances were obtained under both fuels at all the temperatures investigated. This suggested that the barium component promoted the ammonia decomposition sufficiently over the anode even at 600 oC.
This work was supported by JST SICORP Program (Grant Number: JPMJSC2122).
Stabilization of a Hydride Superionic Conducting Phase Via Cation Substitution in Ba-Li Based Oxyhydride
Authors: Yaguchi Hiroshi , Okamoto Kei , Takeiri Fumitaka , Kobayashi Genki 
Published: December 2024

Hydride ions (H–) are attractive charge carriers with basic characteristics suitable for fast ion conduction, including monovalence, moderate ionic size, and large polarizability. The strong reducing property based on the standard redox potential (Eº(H–/H2) = –2.3 V vs. SHE) can lead to high energy density in batteries and high efficiency in energy/material conversion devices. For H– conductors, mixed-anion compounds such as oxyhydrides are currently the primary targets of materials exploration. This is because, compared to simple metal hydrides, the coexistence of multiple anions facilitates the control of parameters essential for developing H– conductors, such as the H– concentration and configuration.
Recently, we reported H– conducting Ba-Li oxyhydrides (BLHO) with the K2NiF4-type structure [1]. BLHO has a stable composition of the highly vacant Ba1.75LiH2.7O0.9 under ambient pressure and forms the superlattice structure at low temperature due to the three types of long-range ordering, namely Heq/VH, Hap/Oap, and Ba/VBa (Heq, Oap, and V
M
represent hydrogen at equatorial anion sites, oxygen at apical anion sites, and a vacancy at M sites, respectively). These long-range orderings are successively disordered upon heating; Ba/VBa and Heq/VH at 300 ºC; Hap/Oap at 350 ºC (each phase is called b-, γ-, d-BLHO from the lower temperature side). The H– conductivity enhances after the β-γ transition to the so-called superionic conduction state, which exhibits conductivity over 10–2 S·cm–1 nearly independent of the temperature. The introduction of structural randomness into BLHO via elemental substitutions should stabilize the γ- and δ-phases at lower temperatures. In this study, we synthesized solid solutions of BLHO in which Li and Ba were partially substituted by cations with different sizes and valences, respectively, and investigated the impact of the elemental substitution on the phase transition behavior and H– conductivities [2 - 4].
[1] F. Takeiri, G. Kobayashi et al., Nat. Mater.,
21, 325–330 (2022)
[2] K. Okamoto, G. Kobayashi et al., J. Mater. Chem. A, 10, 23023-23027 (2022).
[3] K. Okamoto, G. Kobayashi et al., Adv. Sci., 10, 2203541 (2023).
[4] H. Yaguchi, G. Kobayashi et al., (in preparation).

Figure 1
(Invited) Studying Ni-YSZ Fuel Electrode Microstructure and Characteristics Using Symmetric Cells
Authors: Pibulchinda Pattiya , Barnett Scott A 
Published: December 2024

Electrode-supported solid oxide cell (SOC) performance, efficiency, and stability are largely dependent on their Ni-YSZ cermet electrodes and supports. The design variables for these Ni-YSZ layers include the Ni/YSZ ratio, pore former volume fraction/size, thicknesses, and the firing conditions that partly determine their microstructures. These parameters can be used to optimize the electrode by maximizing active triple phase boundary (TPB) density in the functional layer, maximizing gas transport through the support, achieving required conductivity, maintaining mechanical strength, and minimizing overall Ni content.
This study aims to investigate how Ni-YSZ characteristics affect overall electrochemical performance and mechanical strength. In the initial studies, Ni-YSZ electrode-supported symmetric cells with a single uniform Ni-YSZ layer without pore former were studied to focus on functional layer properties. Cells with different Ni contents were compared. Cells were manufactured by laminating tape-cast layers and co-sintering at high temperatures, with a YSZ electrolyte thickness of ~ 10 μm and Ni-YSZ thickness of ~ 150 μm. Initial NiO weight percentages in the NiO-YSZ slurries were varied from 45 to 70% in different cells. Although NiO-YSZ layers with different compositions are expected to have different shrinkages, we found that by sintering the symmetric cells at 1300°C, all cell configurations were free of defects, curvature, or delamination.
Flexural strengths of both the electrodes and symmetric cells were characterized at ambient temperature via three-point bending tests. The NiO-YSZ composite reduction to cermet Ni-YSZ decreases flexural strength. In addition, increases in Ni content decrease flexural strength. The flexural strength results will be compared with values expected based on classic laminate plate theory.
Electrochemical impedance spectroscopy measurements were taken at open circuit voltage in 97% H2-3% H2O at 650°C, 700°C, 750°C, and 800°C. The impedance results fitted well using an equivalent circuit model that includes Ohmic, transmission line, and Warburg resistance elements. The Warburg resistance, which corresponds to gas diffusion processes, decreases significantly with increasing Ni content since most of the porosity results from the reduction of NiO to Ni. In these low steam conditions, the Warburg resistance element dominates overall impedance in 45 to 65 NiO weight percent electrodes. The 50-weight percent NiO electrode was found to minimize transmission line model resistance. The correlation between impedance results and the measured electrode microstructure (e.g., porosity, tortuosity, and active TPB density) will be discussed.
Advances in Redox-Electrodialysis for Energy-Efficient Desalination
Authors: Su Xiao , Kim Nayeong , Elbert Johannes 
Published: December 2024

Electrochemical separations have rapidly grown in recent years due to advances in functional materials as well as architecture design. By bridging the technologies between redox-based energy storage and desalination, redox-mediated electrodialysis (redox-ED) has been shown to achieve continuous desalination from brackish water to seawater, with reduced energy consumption. Here, we provide an overview the advances in redox-electrodialysis, in terms of materials design as well as electrochemical engineering.
First, by replacing costly and sensitive ion-exchange membranes (IEMs) with robust nanofiltration membranes (NFs), we enable the energy-efficient desalination and removal of organic contaminants.1 NF-enabled redox-polymer ED demonstrated desalination down to potable water (<500 μS/cm) in wastewater containing organic substances, while redox-ED with IEM suffered from significant membrane fouling and slower desalination rates.
Second, by combining the water-soluble redox polymers with NFs, we removed a variety of chain lengths of carboxylates and per- and polyfluorinated substances (PFAS), while preventing membrane fouling and polymer crossover into the feed solution. Finally, we discuss the application of redox-electrodialysis systems for facilitating downstream processing in biomanufacturing, through the retention of proteins and organic acids from complex food and fermentation streams. 2-4 In general, we envision redox-electrodialysis platforms to gain increased attention for both water purification and multicomponent industrial separations.

References

(1) Kim, N.; Elbert, J.; Kim, C.; Su, X. Redox-Copolymers for Nanofiltration-Enabled Electrodialysis. ACS Energy Letters
2023, 8 (5), 2097-2105.
(2) Kim, N.; Lee, J.; Su, X. Precision Tuning of Highly Selective Polyelectrolyte Membranes for Redox‐Mediated Electrochemical Separation of Organic Acids. Advanced Functional Materials
2023, 33 (12), 2211645.
(3) Kim, N.; Oh, W.; Knust, K. N.; Zazyki Galetto, F. b.; Su, X. Molecularly Selective Polymer Interfaces for Electrochemical Separations. Langmuir
2023, 39 (47), 16685-16700.
(4) Kim, N.; Jeon, J.; Elbert, J.; Kim, C.; Su, X. Redox-mediated electrochemical desalination for waste valorization in dairy production. Chemical Engineering Journal
2022, 428, 131082.
Innovative Anode Design Incorporating Sub-Catalyst Layer for Proton Exchange Membrane Water Electrolyzers with Ultra-Low Iridium Loading
Authors: Hsu Yu Wei , Chueh Lu Yu , Pan Yung-Tin 
Published: December 2024

Proton exchange membrane water electrolyzers (PEMWE) have garnered increasing attention in recent years due to their capability to produce clean, high-purity hydrogen. The optimization of the catalyst layer structure within these systems is critical, particularly in reducing the loading of platinum-group metal (PGM) anode catalysts. Under conditions of ultralow iridium loading, ion and mass transport are severely impeded, which hampers the kinetic performance of oxygen evolution reaction (OER) catalysts.
In this study, we propose an innovative membrane electrode assembly (MEA) design for PEMWE, wherein an ultra-thin sub-catalyst layer is constructed atop the conventional catalyst layer. This sub-catalyst layer, fabricated via spray coating with an ultra-low iridium loading of less than 0.05 mg/cm², possesses a high surface area and is engineered to enhance the interfacial contact area between the catalyst layer and the porous transport layer. The integration of this sub-catalyst layer markedly reduces both kinetic and ohmic resistances, thereby lowering the overall overpotential.
Our findings demonstrate that this novel approach results in a significant increase in the current density of the electrolyzer by 400 mA/cm² and a reduction in high-frequency resistance (HFR) by 35 mΩ cm², when compared to the conventional MEA structure. This study highlights the potential of the proposed MEA design to improve the efficiency and performance of PEMWE systems, contributing to the advancement of clean hydrogen production technologies.
P and Bi Doped Pt-Zn Alloy as an Effective Electrocatalyst for Hydrogen Evolution Reaction: A First-Principles Study
Authors: Park Yonghak , Han Byungchan 
Published: December 2024

Platinum (Pt) is a highly effective catalyst for the hydrogen evolution reaction (HER), but its high cost and scarcity have spurred efforts to reduce Pt usage without compromising catalytic performance. Various strategies, such as alloying Pt with earth-abundant elements and doping with other elements to modify the electronic structure and improve activity, have been explored to achieve this objective.
In this study, we propose a phosphorus (P) and bismuth (Bi) doped Pt-Zn catalyst with a reduced platinum content and enhanced HER activity. Using First-Principles calculations, we identified the stable structure of the PtZn alloy and the optimal doping configurations of P and Bi. In addition, we calculated the adsorption energies of a key intermediate to construct the reaction free energy diagram, validating the enhanced catalytic activity of the P and Bi doped Pt-Zn catalyst. To gain atomistic-level insights, we performed detailed calculations to analyze the electronic structure of the doped configurations, revealing the role of these dopants in optimizing the electronic structure at the active sites. Our analysis demonstrates that the introduction of P and Bi not only stabilizes the catalyst structure but also effectively modifies the electronic properties to improve HER activity. This approach offers a promising pathway to develop cost-effective and high-performance Pt-based catalysts for electrochemical applications.
Tribute to Professor Baldassare Di Bartolo - Rino
Authors: Bettinelli Marco , Collins John , Mishra Kailash C , Zych Eugeniusz 
Published: December 2024

In the realm of science, there are those whose brilliance illuminates not only the paths of discovery but also the hearts and minds of their colleagues and students. Professor Baldassare Di Bartolo stands as a beacon among such luminaries, a figure whose scientific achievements, contributions to the field, and service to society are nothing short of exemplary.
With a keen intellect and boundless passion, he has made indelible marks across multiple disciplines, leaving a legacy that enriches our understanding of the universe. Professor Di Bartolo's scientific achievements are monuments to his dedication and ingenuity. His groundbreaking research has expanded the boundaries of our comprehension, from the intricate workings of quantum mechanics to the mysteries of photonics and beyond. Through his pioneering work, he has unlocked new insights into the fundamental nature of light and matter, paving the way for transformative advancements.
Yet, Professor Di Bartolo's impact extends far beyond the confines of the laboratory. With a steadfast commitment to disseminating knowledge, he has served as a catalyst for intellectual exchange and collaboration. Through his tireless efforts in organizing conferences and seminars, he has fostered vibrant communities of scholars, fostering dialogue and cross-pollination of ideas that have propelled scientific inquiry forward.
However, perhaps the true measure of Professor Di Bartolo's greatness lies not merely in his scientific achievements but in the profound impact he has had on the lives of those around him. His wisdom, generosity, and unwavering support have shaped countless careers, nurturing the next wave of scientific pioneers who carry his legacy into the future.
Professor Baltassare Di Bartolo, Rino, we salute you not only for what you have accomplished but for the light you have kindled in the hearts of all who have had the privilege of knowing you.

Figure 1
(Invited) Photoluminescence and Scintillation Properties of Heavy Single Crystal Scintillators for X- and Gamma-Ray Detection
Authors: Yanagida Takayuki , Nakauchi Daisuke , Kato Takumi , Kawaguchi Noriaki 
Published: December 2024

Scintillators are one of the luminescent materials, and have a function to convert a quantum of ionizing radiation to thousands of low energy photons immediately via interactions between the material and ionizing radiation [1,2]. Generally, scintillators are combined with photodetectors, and when the scintillation photons are emitted from the scintillator, photodetectors convert them to electrical signals. When the target ionizing radiation is high energy photons such as X- and gamma-rays, heavy materials are preferable for scintillators since the detection efficiency against high energy photons depends on density and effective atomic number. Up to now, many types of materials have been examined for scintillators, such as single crystals, glasses, and opaque and transparent ceramics [2]. Among them, bulk single crystalline scintillators have been applied for scintillation detectors owing to a superior optical quality including high transmittance and luminescence efficiency.
In the conference, some recent results of development of heavy scintillators mainly containing Lu, Hf, Ta and Tl are introduced. These materials were synthesized by some single crystal growth techniques such as the floating zone and bridgman method. After the synthesis, they were examined on optical (photoluminescence excitation and emission spectra and decay curve) and scintillation (scintillation emission spectrum, decay curve, afterglow and pulse height) properties. In Lu-based crystals, rare earth doped Lu2O3 crystals are introduced, and especially, Tb- and Eu-doped ones show a high scintillation light yield. In Hf-based ones, some results of rare earth doped AEHfO3 (AE = alkali earth) crystals are presented, and Ce-doped (Mg,Ca)HfO3 shows a high scintillation light yield [3]. Among Ta-based crystals, Mg4(Nb,Ta)2O9 crystals have a high light yield due to charge transfer luminescence of Ta/Nb and O [4]. In Tl-based crystalline compounds, TlMgCl3 shows a high light yield and energy resolution [5]. In the conference, these results will be introduced.
References
[1] T. Yanagida, Proc. Jpn. Acad., Ser. B, Phys. Biol. Sci., 94(2) 75 (2018).
[2] T. Yanagida, T. Kato, D. Nakauchi, N. Kawaguchi, Jpn. J. Appl. Phys., 62 010508 (2023).
[3] H. Fukushima, D. Nakauchi, T. Kato, N. Kawaguchi, T. Yanagida, Jpn. J. Appl. Phys., 62 010506 (2023).
[4] T. Hayashi , K. Ichiba, D. Nakauchi, K. Watanabe, T. Kato, N. Kawaguchi, T. Yanagida, J. Lumin., 255 119614 (2023).
[5] Y. Fujimoto, M. Koshimizu, T. Yanagida, G. Okada, K. Saeki, K. Asai, Jpn. J. Appl. Phys., 55 090301 (2016).