Article
Chemistry, Physical
Pankaj Kumar Singh, Anamika Singh, Vivekanand Kain, Yoshitsugu Kojima, Hiroki Miyaoka, Sanjay Kumar
Summary: Both CaH2 and MgH2 are good candidates for hydrogen storage materials due to their high storage capacity. The MgH2-CaH2 composite may have potential as a mobile hydrogen storage system.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Juan Rogelio Tena-Garcia, Alejandro Casillas-Ramirez, Ricardo Guerrero-Ortiz, David Ricardo Poire de la Cruz, Karina Suarez-Alcantara
Summary: The dehydrogenation temperature of LiAlH4 can be significantly reduced by producing mixtures with ZrCl4 through ball milling at low temperatures. This method allows for efficient hydrogen release by achieving small aggregate size and preventing substantial decomposition. However, the LiAlH4/ZrCl4 mixtures are unstable and difficult to handle. The dehydrogenation pathway is changed in the mixtures, resulting in the formation of Al, LiCl, Zr, and H2 as the main products.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Chemical
Shunfeng Ji, Anran Zeng
Summary: The study analyzed the solubility of hydrogen in atmospheric residues from Venezuela Orinoco, China Liaohe, and China Fengcheng under different reaction conditions, and discussed the activation of hydrogen during the upgrading process. The results showed that lighter components produced in the reaction can increase hydrogen solubility, while sulphur, metals, and naphthenic aromatic structures have a positive effect on hydrogen activation.
Article
Chemistry, Applied
Andrey Galukhin, Roman Nosov, Guzel Taimova, Ilya Nikolaev, Daut Islamov, Sergey Vyazovkin
Summary: The kinetics of liquid-state polymerization of adamantane-based dicyanate ester was studied for the first time, showing a transition from kinetic- to diffusion-controlled regime in the later stages. The experimental results confirmed the hypothesis about the influence of the cyanate ester molecule's rigidity on its reactivity and the thermal properties of the corresponding polymer product.
REACTIVE & FUNCTIONAL POLYMERS
(2021)
Article
Chemistry, Physical
Zhenyang Wang, Jianliang Zhang, Baojun Zhao, Hongyuan Fu, Jing Pang
Summary: This study proposes a novel method for obtaining instantaneous activation energy, providing a quantitative basis for kinetics segmentation and rate-limiting mechanism determination. The results reveal that different pore characteristics and changes in value directly influence the corresponding rate limiting mechanisms and restriction degrees.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Hong Li, Zhenxiong Huang, Bohong Chen, Yu Jiang, Chuanhua Li, Wei Xiao, Xuemin Yan
Summary: This study successfully improved the electrochemical performance of MnO2-based cathodes for aqueous Zn-ion batteries by doping group VIII metals. In-situ X-ray diffraction and transmission electron microscope studies revealed a structural transition in the Fe-doped MnO2 electrode during discharging and subsequent Zn extraction processes.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Furong Chen, Wei Lv, Gangwei Zhou, Zhuoliang Liu, Mansheng Chu, Xuewei Lv
Summary: The effects of pre-oxidation treatment on the hydrogen-rich reduction of Panzhihua ilmenite concentrate powder were investigated. The study found that pre-oxidation treatment and increased H2 concentration accelerated the hydrogen-rich reduction rate. The reduction process can be divided into two stages: Fe3+ to Fe2+ and Fe2+ to Fe. The apparent activation energies of both raw and pre-oxidized ilmenite concentrates were reduced by pre-oxidation treatment.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Baoguo Yuan, Deguo Qian, Aichuang Tang, Yangxi Song, Xiaoxue Zhang, Zhongyue Huang
Summary: The hydrogen absorption characteristics and kinetics of TC21 alloy under different initial hydrogen pressures and temperatures were studied. Equilibrium was reached during the heat preservation and cooling stages, with higher temperature and pressure leading to faster equilibration. XRD analysis revealed the phase compositions of the hydrogenated TC21 alloy. The hydrogen content varied with hydrogenation temperature and pressure, and the activation energy for hydrogen absorption in TC21 alloy was approximately 18.304 kJ/mol.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Yanghuan Zhang, Wei Zhang, Xin Wei, Zeming Yuan, Jingliang Gao, Shihai Guo, Huiping Ren
Summary: The addition of TiO2 in magnesium based materials improves the efficiency of mechanical milling and enhances the hydrogen storage performance, especially in the as-milled (x = 5) alloy. The alloy exhibits an amorphous and nanocrystalline structure, and the TiO2 content has a slight effect on the thermodynamic properties of the alloys. The optimal hydrogen storage property is shown in the as-milled (x = 5) alloy due to its minimum dehydrogenation apparent activation energy.
MATERIALS CHARACTERIZATION
(2021)
Article
Biochemistry & Molecular Biology
Chiuyen Phan, Jie Shen, Kaxi Yu, Jiyong Liu, Guping Tang
Summary: Sorafenib and its salts were prepared to improve solubility, and the distinct roles of water molecules in stabilizing crystal structures were investigated. The crystal structures of sorafenib hydrochloride monohydrate and sorafenib hydrobromide monohydrate were found to be isomorphous, with similar unit cell dimensions. The tabletability and solubility of these salts were shown to be improved compared to the free drug.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Physical
Haiming Wang, Bingjie Liu, Guangyao Yang, Changfu You
Summary: The multistep kinetics of Fe2O3 reduction by H2 was studied using data deconvolution. The reduction process was conducted isothermally in a TGA apparatus at temperatures ranging from 750 to 950 degrees C. The stepwise reduction of Fe2O3 was successfully decoupled without controlling the reduction gas atmosphere. The deconvoluted data accurately described the overlapping and reaction rates of each reduction step.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Polymer Science
Sergey Vyazovkin, Andrey Galukhin
Summary: The application of the Ozawa-Avrami model to crosslinking polymerizations has some problems, including limited applicability to processes that follow the Avrami model, systematic dependence of temperature on the Avrami index in autocatalytic or decelerating kinetics, inability to accurately calculate activation energy and preexponential factor using the Arrhenius equation, and the possibility of questionable interpretations due to breakpoints in Arrhenius plots.
Article
Chemistry, Physical
Yanghuan Zhang, Hanfeng Sun, Wei Zhang, Zeming Yuan, Xin Wei, Jinliang Gao, Huiping Ren
Summary: This study focuses on investigating the effect of Ce partial substitution of La on the comprehensive hydrogen storage performances of La10-xCexMg80Ni10 alloys. It was found that the presence of Ce in the alloys resulted in grain refinement and decreased stability of the hydride, leading to lower dehydrogenation temperature and enthalpy. Additionally, the dehydrogenation activation energy of the alloys was distinctly reduced by composition adjustment, indicating improved hydrogen storage performances.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Multidisciplinary
Elizaveta Cheremisina, Olga Cheremisina, Maria Ponomareva, Viktor Bolotov, Alexander Fedorov
Summary: This study investigated the kinetics of hydrogen sulfide sorption by an unrefined ferromanganese ore containing iron oxides and manganese minerals. Results showed a catalytic effect of iron (III) oxide in reducing the activation energy for H2S sorption. A chemical reaction converting hydrogen sulfide into sulfur and water was identified through X-ray and chromatographic analysis. The study also calculated reaction parameters based on the Bronsted-Polanyi rule for catalytic processes.
Article
Environmental Sciences
Imtiaz Ali Jamro, Guanyi Chen, Sajjad Ali Mangi, Wenchao Ma, Saud Allehyani
Summary: This study investigated the composition and energy potential of university solid waste in China. Gasification experiments were conducted on different components of the waste to determine their thermal degradation behavior and gas release. The results showed that lower heating rates were favorable for higher thermal conversion and gas production.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Chemistry, Physical
Yoshitsugu Kojima, Masakuni Yamaguchi
Summary: The study focused on the work function of metals as an index of ion binding property between metals and hydrogen, and analyzed the relationship between the standard entropy change of metal hydrides and the work function of metals (alloys). It was found that the standard entropy changes of alloy-based metal hydrides linearly increased with the work functions of the alloys, which also increased with the bulk modulus. Additionally, the standard entropy change was proportional to the standard heat of formation due to certain constant relationships between parameters.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Multidisciplinary
Pankaj Kumar Singh, Hiroyuki Gi, Keita Shinzato, Kiyofumi Katagiri, Hiroki Miyaoka, Takayuki Ichikawa, Yoshitsugu Kojima
Summary: The Nb2O5 gel synthesized by simple methods can significantly improve hydrogenation kinetics at room temperature, and has higher catalytic effect than heat-treated Nb2O5 gel. Nb oxides show better catalytic effects compared to Ta oxides and mixtures.
MATERIALS TRANSACTIONS
(2021)
Article
Chemistry, Physical
Yoshitsugu Kojima, Masakuni Yamaguchi
Summary: The thermodynamic analysis of ammonia storage materials revealed that the electronegativity of cations in metal chlorides and the electronegativity difference in metal halides play a crucial role in the stability of ammoniates. The stronger the binding energy, the smaller the entropy change caused by ammonia absorption. The standard entropy change Delta S-0 linearly increases with the natural logarithm of the volume difference Delta V of the ammonia storage materials.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Masakuni Yamaguchi, Hiroki Miyaoka, Yoshitsugu Kojima
Summary: Zirconium phosphate has been studied for its ammonia absorption properties, with calculations showing different standard enthalpy changes for ZrP-NH3 and ZrP-2NH3. P-31 MAS NMR and FT-IR analysis indicated distinct local structures for the absorbed ammonia on ZrP. The study suggests a reaction between nitrogen in ammonia and hydrogen in the phosphate group forming different local structures.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Shashi Sharma, Fangqin Guo, Takayuki Ichikawa, Yoshitsugu Kojima, Ankur Jain, Shivani Agarwal
Summary: The KSiH3 system shows promise as a hydrogen storage alloy system, with TiO catalyst effectively reducing activation energy and improving hydrogenation efficiency.
MATERIALS LETTERS-X
(2021)
Article
Chemistry, Physical
Yoshitsugu Kojima, Masakuni Yamaguchi
Summary: The gravimetric H-2 densities and heats of combustion of ammonia storage tanks were similar to those of liquid H-2 tanks, while the volumetric H-2 densities and heats of combustion were higher. Gray, blue, and green ammonia have different production processes and energy efficiencies, with green ammonia having the lowest production cost.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Masakuni Yamaguchi, Yoshitsugu Kojima, Hiroki Miyaoka
Summary: Zirconium phosphate is a material capable of adsorbing and regenerating ammonia, and can be repeatedly used at high temperatures.
Article
Materials Science, Multidisciplinary
Yoshitsugu Kojima, Masakuni Yamaguchi
Summary: This passage discusses the standard entropy and enthalpy differences between metal oxides, metal peroxides, and metal hydrides, indicating their relationships and the assumption that the entropy of oxygen and hydrogen can be controlled by ideal gas thermodynamics.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Masakuni Yamaguchi, Tomoyuki Ichikawa, Yoshitsugu Kojima, Hiroki Miyaoka
Summary: In this study, the equilibrium pressure of zirconium phosphate during ammonia ab/desorption was measured using cavity ring-down spectroscopy (CRDS). Two-step equilibrium plateau pressure was observed during the ammonia desorption. Hysteresis in zirconium phosphate at different equilibrium pressures during ammonia desorption and absorption was also observed.
Article
Chemistry, Multidisciplinary
Masakuni Yamaguchi, Yoshitsugu Kojima, Hiroki Miyaoka
Summary: This study investigates the regeneration process of ammonia-absorbed zirconium phosphate and finds that it can be regenerated at 473K by reabsorbing ammonia and water, allowing for repeated use.
Article
Chemistry, Multidisciplinary
Yoshitsugu Kojima, Masakuni Yamaguchi, Haruo Sawa, Katsuhide Kikuchi, Noriyuki Hiramitsu, Masahiko Kimbara, Haruyuki Nakanishi, Yasuhiro Takahashi
Summary: The capacitances of porous carbon anodes were determined using a Ni(OH)(2) cathode. The capacitances were found to be 300-700 F g(-1), which is over 3 times higher than those of carbon anodes prepared by electrical double layer formation, indicating the larger capacitances achieved through protium H adsorption in the presence of highly concentrated KOH solution.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Nanxu Zhou, Masakuni Yamaguchi, Hiroki Miyaoka, Yoshitsugu Kojima
Summary: The temperature rise of AB(5)-type alloys by hydrogen adsorption is limited by their critical temperatures (T-c), which can be estimated by the Guldberg rule (T-c = 3/2 T-s) relating the H-2 desorption temperatures of metal hydrides at atmospheric pressure (T-s) to Tc.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Machi Kanna, Hikaru Oyama, Tomoyuki Ichikawa, Keita Yamamoto, Hiroki Miyaoka, Yoshitsugu Kojima, Takayuki Ichikawa
Summary: NaBH4 does not absorb NH3 below 100 kPa, while LiBH4 absorbs NH3 at lower pressures. Mixed borohydrides demonstrate a synergistic phenomenon where they absorb NH3 at low pressures and liquefy above 100 kPa. The kinematic viscosity of the liquefied state changes during NH3 absorption.
CHEMICAL COMMUNICATIONS
(2021)
Review
Energy & Fuels
Hiroki Miyaoka, Takayuki Ichikawa, Yoshitsugu Kojima
Summary: The review systematically investigates reaction cycles based on redox reactions of alkali metals and discusses a potential low-temperature water splitting technology. By utilizing phase transition of alkali metals, the reaction temperatures can be decreased for efficient operation.
JOURNAL OF THE JAPAN INSTITUTE OF ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Yoshitsugu Kojima, Masakuni Yamaguchi
Summary: The standard entropy differences between hydrides and other elements increase with volume differences, and can be roughly expressed by an equation involving the gas constant R.
CHEMICAL COMMUNICATIONS
(2021)
