CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhuoyang Li,Yang Zhang,Guishang Pei,Mengjiao Jiao,Xuewei Lv
MnV 2 O 6 and Mn 2 V 2 O 7 are essential compounds in the manganese salt roasting process for extracting vanadium and serve as excellent battery materials. Determining their thermodynamic properties is of significant theoretical and practical importance. In this study, MnV 2 O 6 and Mn 2 V 2 O 7 were synthesized through solid-state synthesis under a nitrogen atmosphere, and their crystal structures were analyzed using X-ray powder diffraction. The heat capacity of MnV 2 O 6 and Mn 2 V 2 O 7 were measured using relaxation calorimetry over the temperature range of 2–300 K. The entropy at 298.15 K, including magnetic contributions, was calculated as 178.99 ± 5.35 J K -1 ·mol -1 for MnV 2 O 6 and Mn 2 V 2 O 7 for 258.93 ± 6.47 J K -1 ·mol -1 . The standard molar enthalpies of formation were determined using high-temperature solution calorimetry in a molten lead borate solvent, yielding -1997.09 ± 23.97 for MnV 2 O 6 and -2427.71 ± 29.12 kJ mol -1 for Mn 2 V 2 O 7 from their element references. Based on these reliable experimental data, other thermodynamic properties, including enthalpy changes, entropy, and Gibbs free energy, were calculated. Finally, thermodynamic simulations were conducted to analyze phase evolution during the manganese salt roasting process and to evaluate the water solubility of MnV 2 O 6 and Mn 2 V 2 O 7 .
研究领域:
材料科学
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热力学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
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2023
·Vol. 158
·期 12
·
IF 4.4
Song Kun,Jin Xin,Lv Xiaodong,Xin Yuntao,Lv Xuewei
Lithium-ion batteries (LIBs) are widely used in electronic applications because of their high voltage, high specific energy, long lifespan, and other characteristics. Electrode materials have garnered interest as an indispensable component of LIBs. Na 7 [H 2 PV 14 O 42 ] is used as an electrode material because of its excellent properties. In this study, Na 7 [H 2 PV 14 O 42 ] was synthesized by the water bath method using NaVO 3 as the raw material, experimentally characterized, and its thermodynamic data were measured using the Neumann–Kopp rule from 298.15 to 843 K, a Physical Property Measurement System from 15 to 309 K, and the MHTC 96 line from 473 to 773 K. The data were fitted to the Debye–Einstein heat capacity equation at low temperatures and a polynomial function at higher temperatures. The heat capacity equation of Na 7 [H 2 PV 14 O 42 ] was obtained from the fitted curves. The corresponding enthalpy ( ▵ 298.15 T H m ), entropy ( ▵ 298.15 T S m ), and Gibbs energy ( ▵ 298.15 T G m ) (from 298.15 to 800 K) were calculated according to the heat capacity equation. The obtained heat capacity of Na 7 [H 2 PV 14 O 42 ], as a function of temperature, was modeled as Cp = 1502.30 + 0.27T − 2.44E7T −2 J mol −1 K −1 (473–773 K). This study can compensate for the thermodynamic deficiency of Na 7 [H 2 PV 14 O 42 ].
研究领域:
材料科学
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热力学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Xiangrong Li,Chenglin Jiang,Jianguo Liu,Ye Qin,Zhongyu Zhang,Zaibo Liu,Jiazhen Yang,Chuanwei Yan
In this paper, a model for viscosity of high-concentrated additive (methanesulfonic acid) in vanadium electrolyte is reported. Methanesulfonic acid was evaluated as a possible stabilizing agent for the thermal precipitation of supersaturated V(V) solutions at elevated temperatures. Viscosity ( η ) of the ternary solution CH 3 SO 3 H + VOSO 4 + H 2 O was measured between the temperatures 283.15 K and 318.15 K under atmospheric pressure. Based on the viscosity, viscosity B -coefficient, activation energy (Δ μ 0 ≠ 0 ) and Gibbs free energy of activation (Δ G ≠ ) were further calculated. With the help of these paraments, a semi-empirical predicting function is established to estimate the viscosity of high-concentrated additive, i.e. methanesulfonic acid in vanadium electrolyte. AARD of this semi-empirical method is 0.22%, which demonstrates that viscosity estimation for high-concentrated ternary solution CH 3 SO 3 H + VOSO 4 + H 2 O can be achieved.
研究领域:
化学工程
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能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
JinTao He,XueMan Xu,Xia Gui
New phase equilibrium data of CO2 in n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane, and n-eicosane were measured at temperatures from 333.15 to 373.15 K up to 23.73 MPa by a constant-volume method. Thermodynamic properties of Gibbs free energy (ΔsolG), enthalpy change (ΔsolH), entropy change (ΔsolS), and Henry’s coefficient (H) were calculated and analyzed for elucidating the dissolution mechanism of CO2 in alkanes. Results showed that the CO2 solubility increased with increasing pressure but decreased with increasing temperature and carbon number. In addition, increasing carbon number also led to an increase in the minimum miscibility pressure (MMP) of alkanes with CO2 and thus limited CO2 solubility in alkanes.
研究领域:
化学热力学
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石油工程
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DOI
高影响因子
ANALYTICAL CHEMISTRY
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2022
·
IF 8.008
Yamin Ma,Cheng Liu,Lishi Wang
A strategy for the fast analysis of ion transfer/facilitated ion transfer toward a tiny (femtoliter) water-in-oil droplet has been established. This scenario is embodied by the fusion of a w/o microdroplet at the micro liquid/liquid (L/L) interface, with the use of Fourier transform fast-scan cyclic voltammetry (FT-FSCV) to express the apparent half-wave potentials of anions or cations encapsulated inside the w/o microdroplet. First, the half-wave potential is in strict accordance with the transfer Gibbs free energy of either cations or anions. Second, the half-wave potential has been found to be positively proportional to the logarithmic concentration of ions, shedding thermodynamic insight into ion transfer. Third, as an instance of multivalent biopolymers, the transfer of protamine inside the single w/o microdroplet has been investigated. Obvious discrepancies in the behaviors of the fusion impacts at different pH, as well as in the absence and presence of the cationic surfactant DNNS–, are revealed. The internal mechanism of protamine transfer has been thoroughly investigated. This work proposes a strategy to sensitively and quickly determine the transfer Gibbs energy and the concentration of ions encapsulated in a single microdroplet, and it provides the possibility of analyzing the interfacial transfer properties of trace biomacromolecules inside an aqueous micro- or nanoscale droplet.
研究领域:
分析化学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FLUID PHASE EQUILIBRIA
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2015
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IF 2.2
Chunlin Li,Qinbo Wang,Binwei Shen,Zhenhua Xiong,Chuxiong Chen
The solubilities of 5,10,15,20-tetrakis(4-chlorophenyl) porphyrin (abbreviated in p -ClTPP) in ethanol + water solvent mixtures at (293.2–333.2) K and 5,10,15,20-tetrakis(4-chlorophenyl) porphyrin manganese(III) chloride (abbreviated in p -ClTPPMnCl) in ethanol + water solvent mixtures at (303.2–333.2) K were measured. The concentration of ethanol in term of mole fraction on the solubility was studied. It was found that the solubility of p -ClTPP in ethanol + water solvent mixtures increases with the increasing of temperature at constant solvent composition , and decreases with the decreasing mole fraction of ethanol at constant temperature. However, for p -ClTPPMnCl, the solubility increases with the increasing of temperature at the mole fraction of ethanol from (0.6102–0.8597), and decreases with the increasing of temperature at the mole fraction of ethanol from (0.9038–1.0000). The experimental data were correlated with the modified Apelblat equation, and the solubilities correlated by the model were in good agreement with experimental data. Thermodynamic parameters including dissolution enthalpy, dissolution entropy and dissolution Gibbs free energy were calculated with van’t Hoff equation.
研究领域:
化学
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热力学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2018
·
IF 0
Yuan Wang,Cailv Zheng,Yilin Wang,Hanxiang Chen,Yun Xu
A new kind of ionic liquids has been synthesized which comprised double bonds in the structure of anions (DB-ILs). Their physical properties, including densities, viscosities, activation energies and diffusion coefficients were determined. Temperature-dependent Krichevsky-Kasarnovsky (K-K) was used to deal with the data of solubility of CO 2 in DB-ILs, thermo-properties including solve enthalpy (ΔH sol ), entropy (ΔS sol ) and Gibbs free energy (ΔG sol ) were obtained. The research shows that DB-ILs perform well at the capturing CO 2 and can be regenerated four times.
研究领域:
化学工程
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热力学
✓ 已验证
产品关联
DOI
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Chunfeng Yuan,Yongli Shen,Chunyu Zhu,Pei Zhu,Fan Yang,Jinghai Liu,Changhua An
Solar-driven hydrogen production is an ideal way to fundamentally solve energy and environmental issues to some extent. TiO2 as a class of promising photocatalysts has attracted intensive attention. However, low light utilization and serious recombination of photo-induced charge carriers lead to a low efficiency. Herein, black TiO2 (B–TiO2) nanosheets have been first synthesized by H2/Ar plasma treatment, onto which Ru single atoms are anchored by dipping RuCl3 solution. X-ray absorption fine spectra reveal that the Ru–O coordination number is ∼5 from the scattering between the Ru center and O atoms of B–TiO2, demonstrating the strong interplay between Ru atoms with TiO2. Density functional theory (DFT) simulations and photoelectrochemical tests clarify that the introduction of Ru single-atoms produces impurity levels, which serves as charge-trapping sites, and facilitates the photo-generated electron separation and transportation. Furthermore, the Gibbs free-energy of the adsorbed H* over RuSAs/B–TiO2 is much closer to zero compared to that of pristine TiO2, thus considerably boosting the photocatalytic performance. The hydrogen evolution over RuSAs/B–TiO2 reaches 17.81 mmol/g/h with an apparent quantum efficiency (AQE) of 21.3% at 365 nm. It is expected that this facile strategy can be employed to fabricate other efficient photocatalysts for new energy production and environmental remediation.
研究领域:
材料科学
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能源科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 11
·期 4
·1793-1800
·
IF 14.511
Yu Nie,Tingting Bo,Wei Zhou,Huilin Hu,Xiang Huang,Huaiyuan Wang,Xin Tan,Lequan Liu,Jinhua Ye,Tao Yu
How to regulate the energy barrier of *COOH is the rate determining step of the photocatalytic reduction of CO2 to produce gaseous CO. Herein, an appropriate Zn vacancy on ZnIn2S4 was synthesised to achieve the desired photocatalytic CO2 reduction capacity (CO: 5.63 mmol g−1 h−1) and selectivity (CO: 97.9%). Various sulfhydryl groups were selected to regulate the Zn vacancy formation in ZnIn2S4, which directly generated the unsaturated coordination state of the sulfur adjacent to the Zn vacancy accompanied by less electrons when compared to ZnIn2S4 without Zn vacancy. Comprehensive experimental analysis and theoretical calculations demonstrated that the appropriate Zn vacancy tuned the Gibbs free energy of *COOH from the endothermic process to the exothermic process in the process of the photoreduction CO2. This work provided an engineering method for cation vacancies and improvement of the efficiency of photocatalytic CO2 reduction by adjusting the energy barrier of intermediate.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Fangxu Dai,Mingming Zhang,Qian Chen,Mingzhong Mi,Zhenjiang Li,Jishu Han,Jun Xing,Shouhua Feng,Lei Wang
Developing highly efficient and low-cost photocatalysts for CO 2 reduction is of critical importance for the conversion of CO 2 to value-added chemicals. Here we report a Co-based zeolitic imidazole framework (ZIF-67) based photocatalyst with exceptional photocatalytic activity and durability for CO 2 reduction. ZIF-67 is doped with dicyandiamide (DCD), the intermediate link with the trace Ru cocatalyst (0.0127 wt. %). The underlying reduction mechanism was unraveled by the joint experiment-theory study. The strong orbital coupling of ZIF-67-DCD-Ru series structure leads to strong CO 2 adsorption, electron enrichment on cocatalyst, and minimum Gibbs free energy barrier of CO generation. The synthesized ZIF-67/DCD/Ru sample exhibits excellent CO 2 photoreduction performance with a CO generation rate of 1495 mmol g Ru −1 h −1 and achieves a record turnover frequency (TOF) of 151 h −1 , representing top-level photocatalytic activity among all reported ZIFs-based photocatalysts. For the first time, our work points out a novel way to achieve high activity of ultralow noble metal loading photocatalyst and provides an in-depth understanding of the advances of the series structure.
研究领域:
材料科学
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化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 3
·657
·
IF 4.2
Heyang Xu,Xilin She,Haolin Li,Chuanhui Wang,Shuai Chen,Lipeng Diao,Ping Lu,Longwei Li,Liwen Tan,Jin Sun,Yihui Zou
Transition metal phosphides (TMPs) have been widely studied for water decomposition for their monocatalytic property for anodic or cathodic reactions. However, their bifunctional catalytic activity still remains a major challenge. Herein, hexagonal nickel-cobalt bimetallic phosphide nanoneedles with 1–3 μm length and 15–30 nm diameter supported on NF (NixCo2−xP NDs/NF) with adjusted electron structure have been successfully prepared. The overall alkaline water electrolyzer composed of the optimal anode (Ni0.67Co1.33P NDs/NF) and cathode (Ni1.01Co0.99P NDs/NF) provide 100 mA cm−2at 1.62 V. Gibbs Free Energy for reaction paths proves that the active site in the hydrogen evolution reaction (HER) is Ni and the oxygen evolution reaction (OER) is Co in NixCo2−xP, respectively. In the HER process, Co-doping can result in an apparent accumulation of charge around Ni active sites in favor of promoting HER activity of Ni sites, and ΔGH*of 0.19 eV is achieved. In the OER process, the abundant electron transfer around Co-active sites results in the excellent ability to adsorb and desorb *O and *OOH intermediates and an effectively reduced ∆GRDSof 0.37 eV. This research explains the regulation of electronic structure change on the active sites of bimetallic materials and provides an effective way to design a stable and effective electrocatalytic decomposition of alkaline water.
研究领域:
材料科学
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电化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Zhuoyang Li,Guishang Pei,Mengjiao Jiao,Yongda Li,Ningyu Zhang,Xuewei Lv
MnV 2 O 6 and Mn 2 V 2 O 7 are the key compounds during the manganese salt roasting for extracting vanadium from vanadium bearing slag. Thermodynamic properties of MnV 2 O 6 and Mn 2 V 2 O 7 are dispensable to get insight into the multi-phase reaction mechanism and clarify the phase evolution. In this study, the MnV 2 O 6 and Mn 2 V 2 O 7 compounds were synthesized through solid-state roasting routes under a nitrogen gas atmosphere, and their crystal structure and thermodynamic properties were determined using X-ray powder diffraction, differential scanning calorimetry, and drop calorimetry. The enthalpy increments of MnV 2 O 6 and Mn 2 V 2 O 7 were experimentally measured for temperatures ranging from 573 K to 1023 K and 573 K to 1173 K, respectively, using drop calorimetry for the first time. Based on the experimentally measured enthalpy increments, the temperature dependence of the molar heat capacity of MnV 2 O 6 and Mn 2 V 2 O 7 was then derived. Furthermore, thermodynamic properties such as enthalpy, entropy, and Gibbs free energy were also calculated. Finally, the Gibbs free energy of the chemical reactions during the roasting of vanadium slag was evaluated, and compared with other roasting techniques.
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）