CHEMICAL ENGINEERING JOURNAL
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2026
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IF 12.5
Yali Wang,Hongbao Ren,Ruizhi Cui,Bo Zhang,Qiuye Yang,Wu Li
A glycerol-water coordination method was developed to prepare high-pure KCl from K(Cl, Br) solid solutions. • Glycerol inhibits Br − from entering the KCl lattice. 30 wt% mixed solvent shows better separation performance. • KCl with 99.994% purity and 97.30% yield was obtained, while bromide was concentrated in the liquid phase. High-purity KCl is essential for semiconductors and laser crystals, yet even trace bromine severely compromises its performance. During the preparation of KCl via underground brine crystallization, Br − readily enters the KCl lattice to replace Cl − , forming crystals with a single-salt structure rather than a simple mixture. This makes it difficult to use conventional separation methods to produce high-purity KCl. To address this issue, this study proposes a separation strategy that involves intervening in the recrystallization process by regulating coordination interactions within the solvent system, thereby yielding ultra-pure potassium chloride. Systematic studies involving phase equilibrium experiments, solid-liquid phase characterization and molecular simulations indicate that as the number of hydroxyl groups in the alcohol molecule increases, the solvent's separation capacity increases accordingly, with glycerol exhibiting the best performance. As the simplest trihydric alcohol, glycerol's three hydroxyl groups create distinct solvation environments for Cl − and Br − , thereby inhibiting Br − from occupying the KCl lattice during the concentration and crystallization processes. Furthermore, the introduction of 30 wt% mass water inhibits intermolecular hydrogen bonding and self-aggregation of glycerol, releasing free coordination sites and significantly increasing the solubility of KCl in the system (from 1.7 wt% to 9.63 wt%), thereby further optimizing separation efficiency. The separation process, designed based on the phase diagram of the KCl − KBr − Gly(30 wt%) − H₂O system at 298.15 K, enables the efficient recovery of high-purity KCl (purity up to 99.9940%, recovery rate of 97.30%) and the simultaneous enrichment of bromine resources in the liquid phase (bromine content increased from 3.36 wt% to 44.30 wt%).
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2026
·
IF 19.7
Wendong Wang,Fangsong Guo,Longmei Shang,Kang Sun,Dandan Song,Jianchun Jiang,Guowu Zhan
Pressure-driven reconstruction forms Ni-O-K single-atom interfaces. • Near-equilibrium CO 2 conversion (∼58%) with ∼100% CO selectivity. • Exceptional stability over 200 h without sintering or deactivation. • Ni-O-K sites lower E a and suppress methanation. • Carboxyl pathway dominates over formate route. Achieving simultaneous high activity, selectivity, and stability in single-atom catalysts (SACs) under high-temperature conditions remains a significant challenge, primarily due to the difficulty in precisely controlling the coordination environment of metal centers. Here, we demonstrate that alkali ion (e.g., K + ) modification of both Ni single atoms and their carbon nitride (CN) support enables exceptional performance in the reverse water-gas shift (RWGS) reaction. The resulting Ni@K-CN catalyst achieves near-equilibrium CO 2 conversion with nearly 100% CO selectivity across a broad temperature range (400–600 ℃), alongside remarkable long-term stability. This performance substantially surpasses that of the K-free analogue and ranks among the best-reported non-noble metal RWGS catalysts. Operando studies reveal that the catalyst undergoes a thermodynamically driven in-situ reconstruction under high pressure reaction conditions, forming atomically dispersed Ni-O-K interfacial sites within a restructured carbon nitride matrix. Density functional theory calculations reveal that these sites markedly lower the apparent activation energy ( E a = 41.5 vs. 131.4 kJ·mol −1 ), modulate the electronic structure of Ni and surface-adsorbate interactions, and thereby promote a low-energy-barrier carboxyl pathway while kinetically suppressing methanation. This work establishes a design strategy based on alkali-mediated dynamic reconstruction to create highly stable and selective SACs for demanding high-temperature catalytic processes. Download: Download high-res image (174KB) Download: Download full-size image
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2026
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IF 2.4
Jia Xu,Xun Wang,Tongqing Wang,Ziwei Hu,Ruyi Lin,Dan Li,Yong Ma,Lingzong Meng,Yafei Guo,Guangli Zhou,Tianlong Deng
The isopiestic equilibria in the system Na2CO3–Cs2CO3–H2O at 308.15 K were investigated with an improved isopiestic method with a modified gravimetric isopiestic apparatus. The water activities and osmotic coefficients were determined based on the calcium chloride standard reference solution. The equilibrium vapor pressure was calculated with the water activity. Combining the Pitzer binary parameters of Na2CO3, the Pitzer binary parameters β(0), β(1), and Cφ of Cs2CO3 and Pitzer mixing parameters θNa+, Cs+ and ψNa+, Cs+, CO32– were fitted with the experimental osmotic coefficients on the basis of the Pitzer model. The water activities were then calculated by the Pitzer parameters, and the good agreement between the calculated water activities and experimental results of this ternary system indicated that the Pitzer parameters obtained in this work were reliable. The thermodynamic data and Pitzer parameters obtained in this work can provide fundamental thermodynamic data for development of universal chemical models for brine systems containing cesium carbonate.
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APPLIED SURFACE SCIENCE
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2025
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IF 6.9
Jingce Bi,Nianzhu Yang,Huichun Xue,Ningning Liu,Yi Wang,Xia Zhang,Zhuopeng Wang,Lin Zhu,Yide Han
Molten salt-assisted pyrolysis has emerged as an effective strategy for engineering defective/doped g-C 3 N 4 photocatalysts for CO 2 reduction. While K + incorporation enhances interlayer charge transport, excessive K + generates detrimental nitrogen vacancies that destabilize the heptazine framework and compromise carrier mobility. Herein, we developed S/K co-doped graphitic carbon nitride (g-C 3 N 4 ) with tunable nitrogen vacancies (denoted SWCN-M) via molten salt (KCl-LiCl) pyrolysis of sulfur-containing supramolecular precursors (melamine with thiourea or thioacetamide). The nitrogen vacancy concentration is precisely modulated by the choice of sulfur precursor (thiourea vs. thioacetamide) to optimize the synergy effect of K + -N-vacancy, and eventually boosting photocatalytic performance. The thiourea-derived SWCN-M TU achieves a CO evolution rate of 165.7 μmol g −1 h −1 , outperforming its thioacetamide analogue (SWCN-M TAA , 90.4 μmol g −1 h −1 ), pristine WCN (53.8 μmol g −1 h −1 ), and K-doped WCN-M (64.3 μmol g −1 h −1 ) by factors of 1.8, 3.1, and 2.6, respectively. DFT calculation results reveal that S-doping induces charge localization, elevating the N-vacancy formation energy via Coulombic repulsion with K + . This work advances the rational design of vacancy-engineered carbon nitride for photocatalytic CO 2 reduction
研究领域:
材料科学
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光催化
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环境化学
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能量转换
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纳米材料
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2025
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IF 3.5
Hai Li,Jiahao Huang,Xin Tan,Xiaofang Lai,Jun Deng,Duan Zhao,Shaoming Zeng,Jikang Jian
Three layered quaternary sulfides, A CuZnS 2 ( A = K, Rb, Cs) have been synthesized by a facile solvothermal method using ethylenediamine as solvent and characterized by a combination of structural, magnetic, and optical measurements . They adopt the ThCr 2 Si 2 -type structure (space group I 4/ mmm ) and are composed of alternating two-dimensional [CuZnS 2 ] −1 layers and alkali metal layers. Based on magnetization and optical measurements, these three compounds are found to be paramagnetic semiconductors. The optical band gap is around 2.75 eV and for the first time two photoluminescence bands are observed for each compound. The green luminescence can be ascribed to a localized Cu + emitting level and the red one to an excitonic state.
研究领域:
材料科学
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无机化学
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固态化学
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光电材料
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光物理
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高影响因子
DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 41
·18012-18018
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IF 4.197
Yongfeng Liu,Yaxiong Yang,Xin Zhang,You Li,Mingxia Gao,Hongge Pan
The thermal dehydrogenation process of the KOH-containing Mg(NH2)2–2LiH system was systematically investigated by identifying changes in the structure and composition of its components by XRD and FTIR. During ball milling, the added KOH reacts with Mg(NH2)2 and LiH to produce MgO, KH and Li2K(NH2)3. During the initial heating process (<120 °C), the newly formed KH and Li2K(NH2)3 react with Mg(NH2)2 and LiH to yield MgNH, LiNH2 and Li3K(NH2)4 along with hydrogen release. Raising the temperature to 185 °C results in a reaction between Mg(NH2)2, MgNH and LiH that gives Li2Mg2N3H3 as the product and further releases hydrogen. As the temperature is increased to 220 °C, Li2Mg2N3H3 reacts with LiNH2 and LiH to produce Li2MgN2H2 and H2. Meanwhile, two parallel reactions between Li2Mg2N3H3, Li3K(NH2)4 and LiH also generate additional hydrogen. Specifically, the KH and Li2K(NH2)3, formed in situ during ball milling, serve as reactants in the dehydrogenation reaction of the Mg(NH2)2–2LiH system, which is responsible for the significantly improved thermodynamics and kinetics of hydrogen storage.
研究领域:
材料科学
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化学工程
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ACS Sustainable Chemistry & Engineering
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2023
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IF 8.4
Fei Fu,Xuan Zhou,Minggui Shen,Dan Wang,Xu Xu,Shibin Shang,Zhanqian Song,Jie Song
With the development of high-frequency communication, the miniaturization of integrated circuits (ICs) has led to interconnected signal delays and losses. The dielectric properties of epoxy resins are no longer satisfactory, because of the presence of polar groups. Herein, a benzocyclobutene-rosin modifier was designed and synthesized to reduce the dielectric constant of epoxy resins. The recross-linking network of benzocyclobutene inhibits the polarizability of the polar groups, and rosin skeletons increase the free volume of epoxy resins. Consequently, the dielectric constant of epoxy resins decreased from 3.12 to 2.72 and their water absorption decreased from 1.06% to 0.861%. The dielectric constant and water absorption are lower than those of most commercial dielectric materials. Additionally, the adhesion of epoxy resins was improved, which broke the contradiction between the dielectric properties and the adhesion of traditional epoxy resins. The modified epoxy resin was finally applied to printed circuit boards. At 15 GHz, its signal loss was 28.8 dB, which was lower than that of a commercial epoxy resin (FR-4), demonstrating that the modified epoxy resin can better meet the miniaturization needs of ICs.
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Frontiers in Chemistry
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2023
·
IF 5.5
Gao Bingliang,Liu Zhiwei,Deng Yifan
Al-Li alloy was prepared by electrodeposition on solid aluminum electrode in a urea-LiCl (77.5:22.5, mol%) molten salt system at 353–393 K. The results of cyclic voltammetry and chronopotentiometry show that underpotential deposition of Li occurs on the Al electrode and forms phases of Al(α) and AlLi(δ) which are confirmed by XRD measurements. Scanning electron microscopy observation of deposits indicates that Al-Li alloy with the thickness of 143 µm was obtained by potentiostatic electrolysis at −0.5 V vs. Li+/Li. The Li content in the alloy obtained at 373 K can reach 6.9 wt%. Galvanostatic electrolysis at 20 A demonstrated that Al-Li alloy coating on aluminum plate can be obtained from urea-LiCl electrolyte at 373 K in the atmosphere.
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PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Zhihao Su,Jionghao Huang,Runhao Wang,Yi Zhang,Lingxing Zeng,Yufei Zhang,Haosen Fan
Covalent organic frameworks (COFs) are regarded as the potential and promising anode materials for potassium ion batteries (PIBs) on account of their robust and porous crystalline structure. In this work, multilayer structural COF connected by double functional groups, including imine and amidogent through a simple solvothermal process, have been successfully synthesized. The multilayer structure of COF can provide fast charge transfer and combine the merits of imine (the restraint of irreversible dissolution) and amidogent (the supply of more active sites). It presents superior potassium storage performance, including the high reversible capacity of 229.5 mAh g −1 at 0.2 A g −1 and outstanding cycling stability of 106.1 mAh g −1 at the high current density of 5.0 A g −1 after 2000 cycles, which is superior to the individual COF. The structural advantages of the covalent organic framework linking by double functional groups ( d -COF) can develop a new road for that COF anode material for PIBs in further research.
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PubMed
高影响因子
FUEL
·
2023
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IF 7.4
Deng Zhao,Haoyuan Feng,Yu Wang,Fei Wang,Huashan Wang,Hua Liu,Hui Liu
The influence mechanism of alkali metal potassium (K) on cellulose pyrolysis is a vague and fundamental key topic in the field of biomass thermal conversion. In this study, the pyrolysis of cellulose and K-impregnated cellulose was compared by in-situ DRIFTS (Diffused Reflectance Infrared Fourier Transform Spectroscopy) and TG (Thermal Gravimetric)–MS (Mass Spectrum) experiment, and quantum chemical calculations were used to verify the peak position and pyrolysis mechanism of infrared (IR) spectroscopy. Stepwise isothermal in-situ DRIFTS was designed to study the reaction path at high temperatures. It was found that in the early stage of pyrolysis, K accelerated the activation of cellulose by attacking the hydrogen bond (H-bond) in the crystal structure of cellulose, increased the dehydration rate between molecules, and promoted the decomposition of cellulose. Simultaneously, it weakened the epoxy–ether bond, inhibited the formation of dehydrated sugar, and promoted the formation of furan. Subsequently, K combined with carbonyl groups to form C–O–K structures, which improved the thermal stability of certain oxygen-containing functional groups such as carbonyls/aldehydes, so that these structures were retained until higher temperature. K promoted the conversion of dehydrated sugars to straight-chain ketones/aldehydes, which led to an increase in carbon conversion. During the coke generation stage, K promoted the formation of disordered carbon and residues, thereby inhibiting coke aromatization. The isothermal in-situ DRIFTS method proposed in this study was demonstrated to better inhibit the high temperature drift of IR spectrum during pyrolysis. It clarified the conversion between functional groups at high temperatures, which is expected to promote the development of other high-temperature pyrolysis mechanism.
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JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
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2023
·Vol. 128
·期 24
·e2023JD039971
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IF 4.4
Lanxiadi Chen,Soleil E. Worthy,Wenjun Gu,Allan K. Bertram,Mingjin Tang
Mineral dust is one of the most abundant types of ice nucleating particles in the atmosphere. During atmospheric transport, mineral dust particles can become coated with inorganic and organic solutes, which can impact their ice nucleation activity. Aminium cations formed from amines are one type of organic solute that can coat mineral dust particles in the atmosphere, but their effects on the ice nucleation activity of mineral dust have not been studied. We investigated the effects of primary, secondary, and tertiary aminium cations with methyl and ethyl groups, as well as ammonium cations, on the ice nucleation activity of K-feldspar, an important type of mineral dust, in the immersion freezing mode at low cation concentrations (0.2–20 mM) using a droplet-freezing apparatus. Ammonium cations substantially increased the ice nucleation activity of K-feldspar, consistent with previous studies. In contrast, primary aminium cations significantly reduced K-feldspar ice nucleation activity, and secondary and tertiary aminium cations had no significant effect (the effect was less than the uncertainty of our measurements). Our combined results are consistent with the following mechanisms: ammonium cations undergo ion exchange with K-feldspar, providing exposed N–H groups for hydrogen bonding with ice; primary aminium cations undergo ion exchange with K-feldspar, exposing a hydrophobic tail that is not effective at nucleating ice; secondary and tertiary aminium cations do not undergo ion exchange with K-feldspar due to steric effects caused by the multiple hydrophobic groups on the cation. Key Points Ammonium cations significantly increased the ice nucleation activity of K-feldspar Primary aminium cations substantially reduced the ice nucleation activity of K-feldspar Secondary and tertiary aminium had limited effects on the ice nucleation activity of K-feldspar due to their inability for ion exchange Plain Language Summary Ice nucleating particles are particles in the atmosphere that can initiate the formation of ice in liquid clouds, impacting cloud properties, precipitation, and climate. Mineral dust is a dominant type of ice nucleating particles in the atmosphere. During atmospheric transport, aminium cations, formed from amine gases which can be abundant in the atmosphere, can coat mineral dust particles altering their ability to nucleate ice. However, the effect of aminium cations on the ice nucleation ability of mineral dust particles has not been studied. We investigated the effects of aminium and ammonium cations on the ice nucleation ability of K-feldspar, an important type of mineral dust and ice nucleating particles in the atmosphere. Our results show that secondary and tertiary aminium cations have no effect on the ice nucleating ability of K-feldspar, but primary aminium cations greatly reduce the ice nucleating ability of K-feldspar. This has possible implications for predicting cloud formation in the atmosphere. We also present a mechanism related to ion exchange that can explain our ice nucleation results.
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Journal of Materiomics
·
2023
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IF 9.4
Jian Guo,Xinrui Yang,Yulong Yang,Shuting Pang,Shan-Tao Zhang,Bin Yang
Ferroelectric Sr 0.6 Ba 0.4 Nb 2 O 6 (SBN) shows typical unfilled tetragonal tungsten bronze structure where 1/6 A sites and all C sites are unoccupied. The presence of such structural vacancy provides the possibility to further modulate the crystal structure and electrical properties. In this work, alkali ions (Li + , Na + , K + ) doped SBN ceramics have been fabricated via solid-solution reaction method. In general, each doping promotes the crystal structure evolves from unfilled toward filled tungsten bronze. However, the different doping ion radius causes the differences in occupying initial structural vacancies, resulting in significantly different electrical properties, Li + doping enhances relaxor characteristic whereas Na + and K + doping lead to normal ferroelectric behavior, accompanying an increase in Curie temperature ( T c ) from 36 °C of SBN to 40, 212, 148 °C of Li + , Na + and K + doping, respectively. Benefiting from improved relaxor degree and high density, the Li + doped SBN displays a good energy storage performance. Since the ratio of Sr/Ba and (Sr + Ba)/Nb has not been changed, this work presents direct evidence for the effect of structural vacancy on crystal structure and properties, as well as inspiration for further work on unfilled tungsten bronze.
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