bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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).
A Guide to Choosing Polymers for Use in Lithium-Ion Cells
Authors: Adamson Anu , Abeysooriya Shanika , Johnson Michel B. , Boetticher Tom , Dahn Jeff R. , Metzger Michael 
Published: December 2024

Every commercial lithium-ion cell made by winding or stacking electrodes uses tape to secure the jelly roll. Recently, it has been shown that lithium-ion cell jelly roll tape is often made out of polyethylene terephthalate (PET)1 and can dissolve into dimethyl terephthalate (DMT), a redox shuttle capable of inducing self-discharge unless effective electrolyte additives are present.2

This is due to ester bonds in PET that are susceptible to methanolysis via methanol and lithium methoxide. that are created in situ during battery operation from dimethyl carbonate (DMC), a ubiquitous solvent used in lithium-ion battery cells’ electrolytes. Effective electrolyte additives suppress the production of methanol and lithium methoxide from DMC, reducing the depolymerization of PET. However, the quantity of electrolyte additives used in commercial cells is low (1-3 wt%), and it has been shown that when ≤2 wt% of vinylene carbonate (VC) is used, most of it will be consumed during the first 200 h of operation.3 Thus, PET and any other polymer with a similar structure could become susceptible to methanolysis over long-term cycling.
Other polymers with a similar chemical structure to PET are also often used in battery manufacturing. Examples include polybutylene terephthalate (PBT) or polyethylene naphthalene (PEN), used in cylindrical cell gaskets4 or metalized polymer current collectors5–7, respectively. Due to their chemical structure being similar to PET, it is reasonable to assume that these polymers might also be susceptible to depolymerization during battery operation, if no effective additives are used. However, in these two use cases, the risk of depolymerization does not only affect self-discharge but also cell safety. If a cell gasket or current collector dissolves during battery operation, this could lead to serious battery safety hazards, e.g., leaks or internal shorts.
This study investigates the chemical stability of the most common polymers used in inactive components of commercial lithium-ion cells, e.g., pouch foils, adhesive tapes1, separators8, gaskets4, and metalized polymer current collectors5–7. The chemically stable and safe polymers to use in batteries are shown. In addition, the potential hazards of using chemically unstable polymers are demonstrated, and possible alternatives for battery manufacturers are proposed.

References

A. Adamson et al., Nat. Mater. (2023) https://www.nature.com/articles/s41563-023-01673-3.

S. Buechele et al., J. Electrochem. Soc., 170, 010511 (2023).

R. Petibon, J. Xia, J. C. Burns, and J. R. Dahn, J. Electrochem.
Soc., 161, A1618–A1624 (2014).

H. Kondo and T. Yamada, (2000) https://patents.google.com/patent/US6025091A/en.

https://metamaterial.com/solutions/battery-materials/.

https://soteriabig.com/technology/.

http://www.dupontteijinfilms.com/.

S. S. Zhang, Journal of Power Sources, 164, 351–364 (2007).
Impact of Sodium Carboxymethylcellulose Binder on the Performance of Lithium-Ion-Batteries for Industrially Relevant Anode Formulations
Authors: Keim Noah , Bauer Werner 
Published: December 2024

To change the solvent in LIB electrodes to water, a water-based polymer binder has to replace the current PVdF binder. This led to Sodium Carboxymethylcellulose (NaCMC) being introduced as a water-soluble binder for LIBs. Due to NaCMC creating a weak connection with the current collector, usually, another additive like SBR rubber is usually added to increase adhesion. Nevertheless, NaCMC dominates the properties of the slurry and influences the structure of the final electrode decisively. Combining the multitude of functionalities of the NaCMC with it being produced from the most abundant polymer in the world, it creates a highly attractive binder, also from an industrial point of view. However, despite widespread use, there is only limited knowledge on how the NaCMC influences key battery properties and battery performance.
The objective of this research is to provide valuable insights into optimizing the composition of lithium-ion battery electrodes for enhanced energy storage and cycling stability, based on a better understanding of the influence of NaCMC. Especially, the influence of varying properties of the NaCMC, like degree of substitution and molecular weight are explained in more detail, which were analysed via adhesion strength testing, Karl-Fischer titration, electrical resistance and potentiostatic cycling. Finally, the influence of the varying NaCMC properties on the battery performance and SEI formation was investigated with post-mortem liquid NMR.
Investigation of Single-Crystal Process for Ni-Rich Layered Oxides Cathode through Solid State Reaction
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Chen Yu-Hsuan , Chen Yu-Fan 
Published: December 2024

Processing of Ni-rich NMC layered oxide cathodes commonly adopt the co-precipitation technique. As a result, very uniform oxide particles in nano-meter range are obtained. However, NMC micro-cracks tend to form in these so-called polycrystals due to volume changes after repeated hundreds of charge/discharge cycles.
In recent years, layered oxides developed by a single-crystal process has received great attention. Ni-rich layered oxides with µm-size grain size tend to give better cycling performance with enhanced structural integrity and less volume change during extended cycling tests. Single-crystal process, in fact, involves heating/calcination of oxide/carbonates/nitrates powder compacts. Accordingly, reactions such as decomposition, chemical reactions, diffusion, oxidation, sintering, grain-growth take place as well. Processing parameters such as temperatures and atmosphere play important roles on the grain growth of Ni- rich layered oxides. Furthermore, the lithiation/oxidation of Ni-containing oxides during single-crystal processing may involve charge compensation resulted from defect reactions. During the different stages of processing, the structural, microstructural and electrical properties of decomposed precursors and resultant layered oxides will be examined using XRD, SEM and DC/AC impedance measurements. CV and charge/discharge tests from assembled coin cells will be used to evaluate electrochemical properties of single-crystal Ni-rich layered oxides.
The Structure and Electrochemical Properties of High-Nickel LiNi1−x−YMnxAlyO2 As Cathode Materials for Lithium-Ion Secondary Batteries
Authors: Jung Da-Hee , Shim Jae-Hyun , Choi Woo-Seong , Kim Ju-Whan 
Published: December 2024

Recently, due to the expansion of the electric vehicle market, there has been an increasing demand for cathode materials, which are essential components of batteries. Commercialized high-energy density lithium-ion batteries primarily use cathode materials such as high-nickel NCM and NCA. However, the cost of cathode materials is increasing due to limited reserves and supply issues of cobalt, the main raw material for NCM and NCA. Therefore, cobalt-free cathode materials are considered an effective solution to the high cobalt price problem and are seen as a means to lower the cost of lithium-ion secondary batteries.
In high-nickel cathode materials, cobalt suppresses Ni/Li mixing, improving the crystallographic structural stability, and enhances lithium ion conductivity, thereby improving the power characteristics. Consequently, materials with different dopants instead of cobalt are being researched for high-nickel cathodes. A prominent example is NMA, which uses aluminum instead of cobalt.
Despite the cost-saving advantages, NMA has several limitations. Compared to cathodes containing cobalt, NMA exhibits drawbacks such as crystallographic structural instability and the formation of lithium dendrites during charging and discharging, leading to degradation in battery lifespan and stability. Various research efforts are underway to address these issues.
This study aims to analyze the structure of NMA manufactured through various process variables and observe the electrochemical changes of NMA according to its crystal structure. This research involves the analysis of crystal structure using X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM), as well as the analysis of electrochemical properties using electrochemical impedance (EIS) spectroscopy techniques.
Effect of the Mxene Introduced to Hollow-Core Shell Binder on Silicon Anode in Lithium Ion Battery
Authors: Seo Yuri , KIM In Seo , Hwang Chan Hee , Lee Jang Hee , Shin Ye Eun , OH Eun-Suok 
Published: December 2024

Mxene-based materials have attracted an attention in the application of next generation lithium ion battries (LIBs) because of their large surface area, excellent conductivity, and well dispertion into water. Our pervious studies on water-dispersible Mxene-containing binder has achieved to the improvement on the electrochemical performance of high-capacity Si anode. In this study, we present a more efficient MXene-containing binder, Mxene-containing acrylic acid-based core-shell structure (MX-ACS) synthesized by in-situ emulsion polymerization. Futhermore, the introduction of MXene segment in MX-ACS improves the conductivity and stability of binder, leading to the extended lifespan and enhanced performance of the batteries.
The effect of Mxene percentage in MX-ACS binder is thoroughly evaluated using various the physical and electrochemical characteristic techniques such as SEM, DSC, TGA, Raman, cyclic performance, EIS, and so on

Keywords: high capacity Si anode, Polymer binder, MXene, acrylic acid-based core-shell

Figure 1
Unravelling the Relationship between Crystallographic Structure and Oxygen Evolution Reaction Activity of Nickel Cobalt Oxide Thin Films
Authors: van Limpt Renee , Lao Mengmeng , Tsampas Michail N. , Creatore Mariadriana 
Published: December 2024

The development of a sustainable energy system relies on the production of green hydrogen. One of the major challenges for water splitting is the synthesis of platinum group metal-free oxygen evolution reaction (OER) electrocatalysts. Spinel nickel cobalt oxides (NCOs) have attracted particular interest due to their stable electrocatalytic performance. The less researched rock-salt NCOs, however, are also promising due to their ability to convert to the OER-active hydroxide phase1. Further development of NCO electrocatalysts requires fundamental understanding of their crystallographic structure-OER performance relationship. This work addresses ~20 nm atomic layer deposited (ALD) NCO thin film systems with a broad composition range to unravel the above-mentioned relationship.
Our previously developed ALD supercycle process2 based on Ni(MeCp)2, CoCp2 and O2 plasma is employed to generate a full range of chemical compositions, such that the phase transition from Ni-rich rock-salt films to Co-rich films at ~55 at.% Co can be observed. Extensive material characterisation reveals that the phase transition is accompanied by an increase in the +3/+2 ratio of the oxidation state of both Ni and Co. Electrochemical analysis in 1M KOH shows an optimal performance for the 30 at.% Co rock-salt film after 500 CV cycles and a synergistic effect between cobalt and nickel such that NCO films are more OER active than Co3O4 and NiO. The films show a composition-dependent activation during CV cycling, where a decrease in activation is observed for increasing Co at.%. No activation is observed for the spinel films. The activation is driven by bulk transformation to the active (oxy)hydroxide phase and is accompanied by an increase in electrochemical surface area (ECSA) up to a factor 8 for rock-salt films. The overpotential after cycling is corrected for the increase in ECSA using an original method, which reveals that Ni-rich spinel structure films are intrinsically more active3.
The use of model systems in combination with extensive material characterisation and prolonged electrochemical testing allows us to distinguish two classes of NCO catalysts, the instantly active and highly stable Co-rich spinel films and the high surface area Ni-rich rock-salt phase which develops upon extensive activation . Placing these results in perspective, we conclude that application of these catalysts on high surface area 3D electrodes would benefit from the more intrinsically active spinel NCO films, whilst activated rock-salt films would be the preferred choice for thin film electrocatalysis studies. These results also show that rock-salt NCO films (<40 at.% Co) could be a more sustainable alternative to the more commonly used spinel NCO films.

1Gebreslase et al. J. Energy Chem. 2022, 67, 101-137

2van Limpt et al. JVSTA, 2023, 41, 032407

3van Limpt et al. Adv. Energy Mat. under review

Figure 1