INORGANIC CHEMISTRY
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2023
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IF 4.6
Jingfang Zhou,Pifu Gong,Mingjun Xia,Aimin Ji,Lifang Zhang,Huiqiang Wu,Qian Wu
Replacing alkali metals (K, Na atoms) by an alkaline-earth metal (Ba atom), α-Ba3Sc2(BO3)4 (high-temperature phase) is successfully obtained by a molten salt method, taking Ba2K1.6Na0.4Sc2(BO3)4 as the parent template. Although both of them exhibit similar layered structures composed of ScO6 and BO3 units, α-Ba3Sc2(BO3)4 shows largely distorted ScO6 octahedra (Δd = 0.56) forced by the uniform tension of a larger space effect from BaO12 polyhedrons, rather than regular ScO6 octahedra like in Ba2K1.6Na0.4Sc2(BO3)4. Experimental measurements and calculated analyses elucidate that distorted ScO6 octahedra in α-Ba3Sc2(BO3)4, displaying a second-order Jahn–Teller (SOJT) effect, enlarge the experimental birefringence up to 0.14@550 nm, while Ba2K1.6Na0.4Sc2(BO3)4 with regular ScO6 octahedra only shows Δn = 0.11 under the same condition. In addition, other optical and thermal properties of the two title compounds were characterized. The experimental results indicate that Ba2K1.6Na0.4Sc2(BO3)4 and α-Ba3Sc2(BO3)4 are promising birefringent materials.
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高影响因子
Catalysts
·
2023
·Vol. 13
·期 2
·450
·
IF 3.9
Muhammad Naeem Younis,Zhiheng Ren,Chunshan Li,Erqiang Wang,Jie Li
The advancing effects of various alkali and alkaline earth metals (inclusive of K, Ca, and Sr) modified Cu/SiO2catalysts, prepared with a modified precipitation-gel method, were investigated for the production of ethanol via hydrogenation of methyl acetate. Our results showed that Sr-doped catalysts exhibited the best and most consistent results during catalytic tests. A series of techniques, including X-ray diffraction technique, Raman spectroscopy, N2adsorption/desorption, N2O titration method, FTIR spectroscopy, and H2temperature, programmed desorption and reduction (TPD and TPR), and X-ray Photoelectron Spectroscopy, which was used to check the detailed characterization of Sr modification in the catalyst and its structural impacts on the properties of the catalyst. These results demonstrated that the addition of 5%Sr could strengthen the intrinsic stability of the catalyst by formulating the appropriate ratio of Cu+/(Cu0+ Cu+) to facilitate catalytic outcome improvement. The addition of 5%Sr-30%Cu/SiO2under the most favorable conditions, resulting in the peak conversion of MA (95%) and ethanol selectivity (96%), indicates its magnificent catalytic stabilizing effects. Furthermore, the best performing catalyst was compared and tested under various conditions (LHSV and temperatures) and a 300 h long life run.Keywords:hydrogenation;methyl acetate;ethanol;strontium
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2019
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IF 2.298
Rui-Zhi Cui,Wu Li,Ya-Ping Dong
The phase equilibria relationship between the quaternary system LiCl–KCl–Li2SO4–K2SO4–H2O and its subsystems LiCl–KCl–H2O and LiCl–Li2SO4–H2O was studied by the isothermal dissolution equilibrium method at 288.15 K, and the corresponding phase diagrams were drawn. At 288.15 K, ternary systems LiCl–KCl–H2O and LiCl–Li2SO4–H2O all belong to the simple type. In the phase diagram of the quaternary system LiCl–KCl–Li2SO4–K2SO4–H2O, there are five equilibrium solid phase crystallization fields: LiCl·2H2O, KCl, Li2SO4·H2O, K2SO4, and Li2SO4·K2SO4. Compared with the multitemperature phase diagrams of this system at 288.15–348.15 K, it was found that the basic configuration of the phase diagrams is the same. As the temperature increased, the phase region of double salt Li2SO4·K2SO4 clearly increased, whereas the phase region of single salt KCl and K2SO4 clearly decreased. On the basis of the experiment, the extended Harvie–Weare model of the Pitzer model was used to predict the solubility data of the quaternary system. The simulated and measured values were basically in good agreement.
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高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jiangping Jing,Zhuoyuan Chen,Chang Feng
Graphitic carbon nitride (g-C 3 N 4 ) usually shows amphoteric property in a neutral solution. In this work, a K&I co-doped g-C 3 N 4 is prepared by simply sintering the mixture of dicyandiamine, KI and I 2 . The K&I co-doping modulates the band structure of g-C 3 N 4 with pulling the Fermi level toward its conduction band minimum. The obtained K&I co-doped g-C 3 N 4 (K&I-C 3 N 4 ) generates positive photocurrents over the whole investigated potential range, exhibiting a typical n-type semiconductor characteristic. Therefore, the K&I co-doping transforms the g-C 3 N 4 from amphoteric to n-type semiconductor. Also, the prepared K&I-C 3 N 4 shows widened light absorption range and enhanced separation efficiency of the photogenerated charge carriers, which results in the dramatically enhanced photoelectrochemical performance.
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高影响因子
ORGANIC ELECTRONICS
·
2018
·
IF 3.68
Chuan Wang,Wu Tang,Zeyi Yao,Yongzhen Chen,Jingfang Pei,Cong Fan
Terephthalic acid (H 2 TP) is initially unveiled to be the first example of organic anodes exhibiting the universal Li-ion, Na-ion and K-ion storage capabilities. In Li-ion half cells, H 2 TP can deliver the average capacities of ∼235 mAh g −1 for 500 cycles; In Na-ion half cells, H 2 TP is reported to deliver the average capacities of ∼200 mAh g −1 for 50 cycles; and in K-ion half cells, H 2 TP can exhibit the average capacities of ∼240 mAh g −1 for 150 cycles. At the same time, the chemical structure and crystal structure of H 2 TP could be transformed into its related metal salts on the anode side due to the low reduction potential. This work indicates that organic electrode materials should own the universal metal-ion-storage (e.g., Li + , Na + , K + , etc.) capability for their large void room of organic solid/crystal state.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2018
·
IF 2.196
Chao Guo,Yangtong Tan,Yu Qian,Siyu Yang
Experimental liquid–liquid equilibria (LLE) data for ternary (methyl propyl ketone + hydroquinone + water) and (methyl propyl ketone + resorcinol + water) systems were determined under atmospheric pressure at T = 298.15, 318.15, and 333.15 K. Distribution coefficients and separation factors were calculated to evaluate extraction effectiveness. Hand, Bachman, and Othmer–Tobias equations were utilized to confirm consistency of experimental LLE data. Thermodynamic NRTL and UNIQUAC models were used to correlate experimental LLE data, and corresponding binary interaction parameters were obtained. The estimated data from the two models agree well with experimental LLE data. The NRTL model gives a better agreement than the UNIQUAC model for ternary (methyl propyl ketone + hydroquinone or resorcinol + water) systems.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2018
·
IF 2.196
Yangtong Tan,Chao Guo,Yu Qian,Siyu Yang
Liquid–liquid equilibrium (LLE) data for the ternary system of (2-pentanone + catechol + water) and (mesityl oxide + catechol + water) was measured under atmospheric pressure at T = (298.2, 318.2 and 333.2) K. The distribution coefficients and separation factors were employed to assess the efficiency of extracting catechol from water. The nonrandom two liquid and universal quasichemical models were applied to correlate the LLE data, and the corresponding binary interaction parameters were obtained. The topological analysis of LLE correlation was used to confirm that the parameters satisfy the Gibbs stability criteria.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Junshuai Chen,Ying Zhang,Taotao Zhan,Qi Zhou,Tian Lan,Maogang He
Methyl caprylate is expected to be one of the main components of biodiesel due to its high cetane number and good oxidation stability. Details of the experimental speeds of sound in methyl caprylate are very scarce, especially in high-temperature regions. Therefore, the speed of sound in liquid methyl caprylate was measured by the Brillouin light scattering method in the temperature range of 298.22–608.38 K and at pressures of up to 10 MPa. The relative expanded uncertainty of the speed of sound is estimated to be less than 1.32% (coverage factor k = 2). The variation of the speed of sound with the temperature and pressure was analyzed. Besides, the correlation for the speed of sound as a function of temperature and pressure is presented based on the experimental data. The absolute average of relative deviation between the experimental data and the calculated results is 0.29%.
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ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Lu Li,Ping Li,Juan Fang,Qingling Li,Haibin Xiao,Hui Zhou,Bo Tang
Considering the important functions of cellular Na+ and K+ together with their cooperative efforts on various biological processes, it is significant to simultaneously detect Na+ and K+ at a single-cell level. Here, we present a novel method to discriminate and quantify simultaneously Na+ and K+ in single cells using a new near-infrared fluorescent probe associated with microchip electrophoresis. The fluorescent probe selectively responds to both Na+ and K+. The microchip electrophoresis allows accurate single-cell manipulation and effective distinction of Na+ and K+. Based on the method, the concentration of Na+ and K+ in single normal and cancer cells was compared, and the variation of Na+ and K+ in single cancer cells during the early stage of apoptotic volume decrease was monitored, which would help us to better understand the critical roles of Na+ and K+ in malignant cells and apoptosis. This method has paved a new way for the research of the synergistic function of Na+ and K+ in the regulation of various biological processes at a single-cell level.
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高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Renping Cao,Qingqiang Xiong,Wenjie Luo,Donglan Wu,Xiao Fen,Xiaoguang Yu
A series of SrAl [4−(4 x )/3] O 7 : x Mn 4+ (0≤ x ≤1.4 mol%) and Sr (1−0.06/2) Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06R + (R + =Li + , Na + , and K + ) phosphors are synthesized by a conventional solid-state reaction method in air. The PLE bands peaking at~325, 395, and 470 nm and the strongest PL band peaking at~660 nm are assigned to the 4 A 2 → 4 T 1 transition of Mn 4+ ion and O 2− –Mn 4+ change transfer band, 4 A 2 → 2 T 1 , 4 A 2 → 4 T 2 , and 2 E → 4 A 2 transitions, respectively. The optimum Mn 4+ doping concentration is about 0.8 mol%. Li + , Na + , and K + ions used as charge compensator can improve observably the PL intensity of SrAl 4 O 7 :Mn 4+ phosphor with excitation 325 nm. The fluorescence lifetimes of SrAl [4−(4×0.008)/3] O 7 :0.008Mn 4+ and Sr [1−0.06/2] Al [4−(4×0.008)/3] O 7 :0.008Mn 4+ ,0.06 R + (R + =Li + , Na + , and K + ) are 0.958, 0.97, 1.113 and 0.965 ms, respectively. The luminous mechanism is explained by schematic energy level diagram of Mn 4+ ion. These experiment results indicate that SrAl 4 O 7 :Mn 4+ ,R + (R + =Li + , Na + , and K + ) phosphors can be used as red emitting phosphor candidate for white LEDs based on a UV (~325 nm) and near UV (~395 nm) bands of LEDs chip.
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Petroleum Science
·
2024
·
IF 6
Jing Tan,Wei Zhang,Xiu-Ling Yan,Hao Zhou,Sher Bahadar Khan,Seitkhan Azat,Shi-You Yan,Hao-Jie Ma,Xin-Tai Su
Humic acids (HAs) are widely used as filtrate and viscosity reducers in drilling fluids. However, their practical utility is limited due to poor stability in salt resistance and high-temperature resistance. High-temperature coal pitch (CP) is a by-product from coal pyrolysis above 650 °C. The substance's molecular structure is characterized by a dense arrangement of aromatic hydrocarbon and alkyl substituents. This unique structure gives it unique chemical properties and excellent drilling performance, surpassing traditional humic acids in drilling operations. Potassium humate is prepared from CP (CP-HA-K) by thermal catalysis. A new type of high-quality humic acid temperature-resistant viscosity-reducer (Graft CP-HA-K polymer) is synthesized with CP-HA-K, hydrolyzed polyacrylonitrile sodium salt (Na-HPAN), urea, formaldehyde, phenol and acrylamide (AAM) as raw materials. The experimental results demonstrate that the most favorable conditions for the catalytic preparation of CP-HA-K are 1 wt% catalyst dosage, 30 wt% KOH dosage, a reaction temperature of 250 °C, and a reaction time of 2 h, resulting in a maximum yield of CP-HA-K of 39.58%. The temperature resistance of the Graft CP-HA-K polymer is measured to be 177.39 °C, which is 55.39 °C higher than that of commercial HA-K. This is due to the abundant presence of amide, hydroxyl, and amine functional groups in the Graft CP-HA-K polymer, which increase the length of the carbon chains, enhance the electrostatic repulsion on the surface of solid particles. After being aged to 120 °C for a specified duration, the Graft CP-HA-K polymer demonstrates significantly higher viscosity reduction (42.12%) compared to commercial HA-K (C-HA-K). Furthermore, the Graft CP-HA-K polymer can tolerate a high salt concentration of 8000 mg·L − 1 , measured after the addition of optimum amount of 3 wt% Graft CP-HA-K polymer. The action mechanism of Graft CP-HA-K polymer on high-temperature drilling fluid is that the Graft CP-HA-K polymer can increase the repulsive force between solid particles and disrupt bentonite's reticulation structure. Overall, this research provides novelty insights into the synthesis of artificial humic acid materials and the development of temperature-resistant viscosity reducers, offering a new avenue for the utilization of CP resources.
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Yunxue Gao,Shuni Li,Quanguo Zhai,Yucheng Jiang,Mancheng Hu
The (solid + liquid) phase equilibrium of the ternary system (NaCl + RbCl + H 2 O) at T = (288.15, 298.15 and 308.15) K was studied by the method of isothermal solution saturation. Moreover, the density and refractive index of the solution was also determined. The solid phase was studied by the Schreinemaker’s wet residue method and verified by X-ray diffraction. The results show that each of the phase diagrams contains one invariant point, two univariant curves, and three crystallization regions. The crystallization region of NaCl increased obviously with the temperature increasing, while the crystallization regions of RbCl and the mixed crystallization region of (NaCl + RbCl) decreased a little. Furthermore, there are break points at the invariant points for density and refractive index curves.
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