Catalysts
·
2020
·Vol. 10
·期 4
·384
·
IF 3.52
Pei Yu,Can Chen,Guangci Li,Zhong Wang,Xuebing Li
The esterification of malic acid using traditional homogenous catalysts suffers from the difficulty in reuse of the catalyst and undesirable side reactions. In this work, Zr(SO4)2/SiO2and Zr(SO4)2/activated carbon (AC) as solid acid catalysts were prepared for malic acid esterification with methanol. The conversion of malic acid over these two catalysts is comparable to that over H2SO4and unsupported Zr(SO4)2∙4H2O catalysts; however; a 99% selectivity of dimethyl malate can be realized on these two supported catalysts, which is much higher than that of conventional H2SO4(75%) and unsupported Zr(SO4)2∙4H2O (80%) catalysts, highlighting the critical role of AC and SiO2supports in tuning the selectivity. We suggest that the surface hydroxyls of AC or lattice O2−ions from SiO2donate electrons to Zr4+in Zr(SO4)2/AC and Zr(SO4)2/SiO2catalysts, which results in the increase in electron density on Zr4+. The enhanced electron density on Zr4+reduces the degree of H delocalization from crystal water and then decreases the Brønsted acid strength. Consequently, the reduced Brønsted acid strength of Zr(SO4)2/AC and Zr(SO4)2/SiO2catalysts suppresses the intermolecular dehydration side reaction. In addition, these two supported catalysts can be easily separated from the reaction system by simple filtration with almost no loss of activity.Keywords:malic acid;catalytic esterification;solid acid catalyst;Zr(SO4)2;intermolecular dehydration
研究领域:
催化
·
化学工程
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Wencheng Lu,Yaoguo Shen,Qiong Wu
The SO 4 tetrahedral group exhibits a low degree of polarization anisotropy, leading to a minimal level of birefringence of sulfates. Our report introduces a novel sulfate compound, RbY(SO 4 ) 2 ·4H 2 O, which exhibits exceptional birefringence in deep ultraviolet sulfates. This crystal possesses dimensions of 6 mm × 4 mm × 1 mm and was synthesized using a straightforward technique involving the evaporation of an aqueous solution. The structure of this substance is characterized by a unique arrangement of SO 4 tetrahedra YO 9 polyhedra, and H 2 O molecules. Each SO 4 moiety contribution two oxygen atoms to share edges with a neighboring YO 9 polyhedron, resulting in significant deformation of these groups. The unique arrangement of edge-sharing arrangement in RbY(SO 4 ) 2 ·4H 2 O results in a birefringence of about 0.045@546 nm. This sets a new record for sulfates in the deep ultraviolet range that have similar non-π-conjugated anionic groups. We elucidate UV–Vis–NIR diffuse-reflection, IR spectra, transmission spectra, and conduct theoretical calculations. These fascinating discoveries will improve our understanding of sulfates and provide valuable insights for studying deep-UV sulfates with strong birefringence.
研究领域:
材料科学
·
晶体学
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2017
·Vol. 43
·期 8
·4353-4368
·
IF 1.369
Yuan Hong,He Jie,Li Ruilan,Ma Xiaoqin
The solid acid catalysts SO 4
2− /TiO 2 were prepared by the impregnation technique under two preparation conditions which were different in calcination temperature and concentration of impregnation solution of H 2 SO 4 . The characterization was carried out by using Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), temperature programmed desorption of NH 3 (NH 3 -TPD), N 2 -BET, X-ray fluorescence and thermal gravity (TG)–differential scanning calorimetry (DSC). The characteristic peaks in the FTIR spectrum were essentially the same within the calcination temperature range of 400–600 °C. The XRD results indicated that the sample could show partial specific peaks of the anatase phase as the calcination temperature was higher than 400 °C. The obvious strong acid and superacid sites of the prepared SO 4
2− /TiO 2 were conformed by the NH 3 -TPD results. The BET surface areas of 102–206 m 2 /g were measured by the N 2 -BET method, and the pore size distributions were essentially mesoporous. The TG–DSC results showed that SO 4
2− /TiO 2 would decompose at about 500 °C in the air. The solid acid SO 4
2− /TiO 2 were used for the epoxidation of castor oil. The lowest iodine value of the product was 52.65/100 g when the reaction temperature was 65 °C, reaction time was 10 h and catalyst loading was 15 wt.%.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Yaoguo Shen,Longjie Huang,Zhifeng Wang,Yingwu Zhou,XiaoLing Xue,Hong Lin,Renwen Yan,Sangen Zhao,Junhua Luo
SO4 tetrahedral groups have weak polarization anisotropy, which thus results in the small birefringence of sulfates. Here, we report new sulfate CsY(SO4)2·4H2O with unprecedented birefringence among deep-ultraviolet (deep-UV) sulfates. Its single crystal (10 mm × 3.5 mm × 1.5 mm) was simply grown by an aqueous solution evaporation technique, and it features a rare layered structure composed of YO9 polyhedra, SO4 tetrahedra, and H2O molecules. Interestingly, each SO4 group donates two oxygen atoms to edge-share with one adjacent YO9 polyhedron and thus causes severe distortion of these groups. The characteristic edge-sharing mode gives CsY(SO4)2·4H2O a large birefringence of ∼0.045@546 nm, which is the maximum among deep-UV sulfates and phosphates with similar non-π-conjugated anionic groups. The ultraviolet–visible-near-infrared diffuse reflection and transmission spectra, infrared spectrum, thermal stability, and theoretical calculations are also presented. The fascinating results will improve our understanding of sulfates and may provide useful insights into the exploration of deep-UV sulfates with large birefringence.
研究领域:
材料科学
·
晶体学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Qi Wang,Shaoxin Song,Ning Nie,Jinshan Tan,Wei Wang
The accurate and sensitive detection of hydrogen peroxide (H 2 O 2 ) is of practical significance in the fields of bioanalysis, medicine, environmental protection as well as food industry. Herein, we design and fabricate NaTb(SO 4 ) 2 nanoparticles (NPs) as novel fluorescent nanoprobes for H 2 O 2 detection. The design strategy is based on the fluorescence quenching occurred during the oxidation of Tb(III) to Tb(IV) upon H 2 O 2 addition. The sensing of NaTb(SO 4 ) 2 NPs to H 2 O 2 is in a “turn-off” mode, and the sensitivity is tunable by the pH due to the pH-dependence of the oxidizing ability of H 2 O 2 . Superior to most of the reported H 2 O 2 sensors, NaTb(SO 4 ) 2 NPs exhibit reliable stability in acidic environment and a more sensitive response to H 2 O 2 with a limit of detection (LOD) down to 0.047 μM at pH = 3.2. Based on its high sensitivity and reliable stability, the NaTb(SO 4 ) 2 NPs is anticipated to find potential applications in the field of biosensors.
研究领域:
生物分析
·
医学检测
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环境科学
·
食品工业
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Yilei Sun,Yao Liu,Haixia Wang,Ze-da Meng,Jae Doc Na,Won-Chun Oh
Sodium-based polyanionic compounds are being widely explored as positive electrode materials for sodium-ion batteries due to the advantages of elevated operating voltage plateaus and exceptional cycling stability. This work investigates the charge/discharge characteristics of a newly developed NASICON-type polyanionic cathode, NaFe2PO4(SO4)2 (NFPS), through X-ray diffraction refinement and cyclic voltammetry. Subsequently, the electrochemical activity is significantly enhanced by Mn2+ doping. Electrochemical testing reveals that Na0.84Mn0.08Fe2PO4(SO4)2 achieves higher capacity and improved rate performance, surpassing pristine NFPS. At a current density of 25 mA g-1, the maximum discharge specific capacity of NFPS-Mn0.08 is 73 mA h g-1. After 60 cycles, the discharge capacity of NFPS-Mn0.08 is 52.7 mA h g-1.
研究领域:
材料科学
·
电化学
·
储能技术
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无机化学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL RESEARCH AND TECHNOLOGY
·
2024
·
IF 1.5
Luyong Zhang,Shibin Wang,Zhencheng Wu,Xueling Hou,Zhihua Yang,Fangfang Zhang,Shilie Pan
Tetrahedral oxygenated groups with large highest occupied molecular orbital-lowest unoccupied molecular orbital (H gaps such as [SO 4 ] are beneficial for deep ultraviolet (DUV) transmission but usually make against generating sufficient birefringence due to the small polarizability anisotropy. Thus, it is extremely difficult to obtain DUV transmission and large birefringence simultaneously in the search for DUV birefringent materials in sulfates. Herein, two new ammonium-rare earth metal sulfates, NH 4 Y(SO 4 ) 2 ·H 2 O and NH 4 YSO 4 F 2 , with DUV transmission are presented. Meanwhile, both exhibit greatly elevated birefringence through the involvement of NH 4 + units, compared to Y 2 (SO 4 ) 3 ·8H 2 O. Their optical properties are further investigated by theoretical calculations, and the effect of the introduction of NH 4 + into yttrium sulfate on optimizing the structures and properties is discussed. This work may provide a new perspective for further exploration of DUV birefringent materials in tetrahedral oxygenated group sulfates.
研究领域:
材料科学
·
光学
·
晶体学
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
Xiaoniu Yu,Chunxiang Qian
Nano-sized CePO 4 @NaCe(SO 4 ) 2 (H 2 O) and CePO 4 with hexagonal phase have been prepared by simply varying the reactant P/Ce molar ratio in bacterial liquid. The phase composition of two samples was checked via Fourier transform infrared spectroscopy (FTIR), energy dispersive analysis of X-rays (EDS) and X-ray diffraction (XRD) analyses, displaying the presence of CePO 4 @NaCe(SO 4 ) 2 (H 2 O) and CePO 4 with average crystallite size are 32.34 and 15.61 nm, respectively. The scanning electron microscopy (SEM) images show that nano-clusters and sphere-like in shape with a narrow diameter distribution were observed in two samples. The transmission electron microscopy (TEM) photographs further indicate obtained CePO 4 @NaCe(SO 4 ) 2 (H 2 O) and CePO 4 nanoparticles correspond to nanosheets and nanorods , respectively. The emission spectra of CePO 4 @NaCe(SO 4 ) 2 (H 2 O) and CePO 4 display a broad band of 300–380 nm range with the strongest emission at 342 nm in the violet region.
研究领域:
材料科学
·
纳米技术
·
化学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2020
·Vol. 646
·期 20
·1688-1695
·
IF 1.24
Shuangsheng Cheng,YuanDong Wu,Dajiang Mei,Shaoguo Wen,Thomas Doert
Four alkali metal bismuth sulfates, NaBi(SO 4 ) 2 · H 2 O ( 1 ) and ABi(SO 4 ) 2 [A = K ( 2 ), Rb ( 3 ), Cs ( 4 )], were successfully synthesized by hydrothermal methods. The crystal structure of 1 features a three-dimensional tunnel framework constructed by BiO 9 tri-capped trigonal prisms and SO 4 tetrahedra interconnected via common corners and edges. Compound 2 exhibits a two-dimensional 2 ∞ [Bi(SO 4 ) 2 ] – double-layered structure, assembled by one-dimensional 1 ∞ [BiS(1)O 4 ] + chains which are linked via S(2)O 4 2– tetrahedra. The isostructural compounds 3 and 4 possess a two-dimensional layered structure, and the layers being composed by BiO 8 square antiprism and SO 4 tetrahedra. The alkali metal cations are located between the layers or in the tunnels of the structures, respectively. The differences in the crystal structures of the title compounds can mainly be attributed to the different sizes of the alkali metal cations and their different coordination environments. Thermogravimetric analysis evidence that compound 1 losses one equivalent of water at 120 °C whereas the anhydrous compounds 2 – 4 are stable up to about 450, 575, and 578 °C, respectively. The solid-state UV/Vis/NIR diffuse reflectance spectra indicate bandgaps of approximately 4.48, 4.43, 3.98, and 3.96 eV for compounds 1 – 4 , respectively.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2015
·
IF 1.839
Xiao Zhao,Dajiang Mei,Jingli Xu,Yuandong Wu
The reactions of A 2 SO 4 ( A = K, Cs) and Sb 2 O 3 with H 2 SO 4 (98%) yielded single crystals of A Sb(SO 4 ) 2 ( A = K, Cs). The crystal structures were investigated by single crystal X-ray diffraction. KSb(SO 4 ) 2 crystallizes in the monoclinic space group P 2 1 / c (No. 14) with lattice parameters a = 10.6745(18), b = 7.1579(12), c = 8.7597(15) Å, β = 91.466(3) ° , V = 669.1(2) Å 3 , Z = 4. CsSb(SO 4 ) 2 crystallizes in the orthorhombic space group P 2 1 2 1 2 1 (No.19) with lattice parameters of a = 5.2429(8), b = 9.5942(16), c = 14.850(2) Å, V = 746.98(20) Å 3 , Z = 4. Both compounds show the Sb 3+ cations in same seesaw-type coordination of oxygen atoms from different SO 4 2 − anions, but exhibit complex two-dimensionally and one-dimensionally linked anionic structures. The alkali cations are located between the layers or chains. The compounds were characterized with FT-IR spectra and solid state UV–vis–NIR diffuse reflectance spectroscopy . The band gaps were estimated at 4.64 eV for KSb(SO 4 ) 2 and 4.68 eV for CsSb(SO 4 ) 2 .
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
TURKISH JOURNAL OF CHEMISTRY
·
2022
·Vol. 45
·期 4
·1133-1145
·
IF 1.151
WANG DING-KAI,ZHAO WEI,CUI MING-YU,GUO TIAN-TIAN,FU SHUI-YUAN,LI WEI-GANG
A series of Zr(SO4)2/SiO2 solid acid catalysts with different Zr(SO4)2 loadings were prepared by water-soluble-impregnation method at room temperature. Then, the prepared catalysts were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectrum, X-ray diffraction, adsorption/desorption of N2, and temperature-programmed desorption of NH3. The results showed that the active component Zr(SO4)2 was successfully adhered to the mesoporous SiO2, and the acid amount of Zr(SO4)2/SiO2 increased with the increasing of the Zr(SO4)2 loadings. Finally, the wheat stalk was used as raw material and depolymerized over Zr(SO4)2/SiO2 to produce ethyl levulinate (EL). The reaction mixture was separated and purified by filtration and vacuum distillation. The kinetic characteristics and the reaction pathway were also studied. A comparative study showed that 20 wt.% Zr(SO4)2/SiO2 exhibited higher catalytic activity. When reaction temperature, time, catalyst dosage and Zr(SO4)2 loadings were 190 °C, 50 min, 20 wt.% and 30 wt.%, the EL yield reached a maximum of 17.14%. The relative content of EL exceeded 90% after three steps of distillation.
✓ 已验证
DOI
高影响因子
Materials Chemistry Frontiers
·
2025
·
IF 6.4
Xiyue Zhang,Yingjie Zhou,Minjie Hou,Xiecheng Yang,Kun Ren,Peng Dong,Jiaqian Qin,Da Zhang,Feng Liang
To meet the urgent requirement for sustainable energy storage technologies, incorporating effective waste management into the design of energy storage materials can achieve a closed-loop supply chain from waste to energy. Herein, extrinsic pseudocapacitive (PDC) cathode materials with different carbon contents were synthesized using FeSO4·7H2O waste through a simple ball milling and annealing process, which enhances sodium storage kinetics and achieves waste recycling. The results indicate that NFSO particles and graphite flakes create a disordered porous structure, which enhances the PDC effect, thus overcoming the slow migration rate of sodium-ions. Specifically, the diffusion coefficient of NFSO/C-10 increased by around an order of magnitude compared to that of NFSO, increasing from 10−12 to 10−11. The discharge capacity reached 84 mA h g−1 at 0.2C (1C = 91 mA g−1). The present work realizes the high-value reuse of waste and highlights the crucial role of the PDC effect in enhancing diffusion dynamics, which opens up a new direction for the design and synthesis of high-rate iron-based sulfate cathode materials.
研究领域:
材料科学
·
能源存储技术
✓ 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）