INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2012
·
IF 2.237
Wenhua Wang,Yucui Hou,Weize Wu,Muge Niu,Weina Liu
The oxidation of coal to produce high-valued benzene polycarboxylic acids (BPCAs), which are obtained currently from diminishing petroleum reserves, is a promising industrial process of the future. Up to now, the yield distribution of BPCAs has not been studied in detail and the mechanism of coal oxidation to BPCAs remains unclear. In this study, Huolinhe lignite was oxidized in a batch reactor by alkali-oxygen oxidation. All 12 kinds of BPCAs obtained were quantified by a new established method. Effects of alkali/coal mass ratio, reaction temperature, initial oxygen pressure, and reaction time on the yield distribution of BPCAs were studied for the first time. The results indicate that BPCAs with four or five carboxyls are the predominant products, and BPCAs with one or two carboxyls are formed in a relatively short time; moreover, the formation of BPCAs with more carboxyls is relatively more sensitive to the salting out effect. CP/MAS 13C NMR spectra and oxidation of model compounds show that phenolic, ether-substituted aromatic, ether, and aldehyde groups are easily converted and that water-soluble acids (WSA) are formed rapidly and largely due to the breakage of these bonds. The step from WSA to BPCAs is relatively slow mainly due to the inertia of the aromatic clusters with attached carboxyls or carboxylate. On the whole, the BPCAs are derived from aromatic clusters through the oxidation of condensed benzene rings, bridges, or peripheral groups that are attached to the aromatic clusters. Possible mother units for BPCAs in the lignite are suggested based on the generally agreed lignite structure.
研究领域:
化学工程
·
煤炭化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2014
·
IF 3.377
Yucui Hou,Jian Li,Shuhang Ren,Muge Niu,Weize Wu
Because of similar properties and very low volatility, isomers of benzene poly(carboxylic acid)s (BPCAs) are very difficult to separate. In this work, we found that isomers of BPCAs could be separated efficiently by quaternary ammonium salts (QASs) via formation of deep eutectic solvents (DESs). Three kinds of QASs were used to separate the isomers of BPCAs, including the isomers of benzene tricarboxylic acids (trimellitic acid, trimesic acid, and hemimellitic acid) and the isomers of benzene dicarboxylic acids (phthalic acid and isophthalic acid). Among the QASs, tetraethylammonium chloride was found to have the best performance, which could completely separate BPCA isomers in methyl ethyl ketone solutions. It was found that the hydrogen bond forming between QAS and BPCA results in the selective separation of BPCA isomers. QAS in DES was regenerated effectively by the antisolvent method, and the regenerated QAS was reused four times with the same high efficiency.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2013
·
IF 2.816
Wenhua Wang,Yucui Hou,Muge Niu,Tong Wu,Weize Wu
Alkali-oxygen oxidation of coals to produce the high-value benzene polycarboxylic acids (BPCAs) is a potential substitute for the petroleum route in the future. However, the high alkali amount consumed in the process is a big obstacle for the practical application. In this work, bituminous coal , the preferential coal rank for this route, was oxidized at temperatures higher than that reported so far. The results show that, as the oxidation temperature increases, a gradually decreased amount of alkali and shortened reaction time are required to get the maximum yield of BPCAs, which remains about 41%. The distributions of BPCAs obtained from the high-temperature oxidation are very close to that of the traditional method. Excess alkali employed in the system can decrease the yield of BPCAs obtained, especially at high temperatures. The enhanced salting out effect by excess alkali concentration delays the diffusion of intermediates to the water phase, during which the mother structures for BPCAs are possibly over-oxidized to carbon dioxide . The high-temperature oxidation of bituminous coal drastically decreases the alkali consumed and improves the production efficiency of BPCAs, which is very important to the industrialization of this process.
研究领域:
化学工程
·
煤化学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANICA CHIMICA ACTA
·
2024
·
IF 2.7
Qiang Zhao,Su-Juan Jin,Zhi Shen,Guo Zang,Wen-Jun Lv
In order to further enrich the research on the synthesis of complexes with polycarboxylic acid ligands and rare earth metal ion. In this study, four rare earth complexes, namely, [Gd(cpia)] n ( 1 ), [Er(cpia)] n ( 2 ), [Pr(cpna) 2 ·2H 2 O] n ( 3 ) and [Gd(Hcpna)(cpna)•3H 2 O] n ( 4 ) have been synthesized by solvothermal method based on 5-(2-carboxyphenoxy)isophthalic acid (H 3 cpia) and 5-(4-carboxyphenoxy)nicotinic acid ligand (H 2 cpna) with rare earth metal ions Pr 3+ , Gd 3+ and Er 3+ . Single crystal X-ray diffraction analyses reveal that complexes 1 , 2 and 3 are two-dimensional network structure, 4 is one-dimensional chain structures. The fluorescence test results show that the fluorescence intensity of complexes 1 and 2 were lower than that of the H 3 cpia ligand, the fluorescence intensity of complexes 3 and 4 were lower than that of the H 2 cpna ligand. Magnetic results indicate complex 1 has ferromagentic behavior and weak antiferromagentic behavior in the complexes 2, 3 and 4 .
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Jie Zhou,Xuyi Zhang,Bicheng Deng,Yabin Huang,Wangqiang Kuang,Xiaojuan Liu,Shengting Kuang,Zhaomin Hao,Wuping Liao
Precise recognition and deep removal of trace thorium from rare earths remains a significant challenge. Herein, we prepared a polycinnamic acid (PCA) resin by emulsion polymerization to achieve efficient separation of thorium from rare earths. The PCA resin leverages its specific pore size, steric hindrance and relatively large electronegativity of thorium to precisely recognize trace thorium ions in rare earth solutions. For instance, a separation factor of 4158 was achieved for Th/Lu at a Lu/Th molar ratio of 350. The resin also exhibited an exceptional adsorption capacity for Th(IV), reaching 405.2 mg/g at 328 K, surpassing most of the previously reported adsorbents. The adsorption process was determined by a combination of intra-particle diffusion and monolayer chemisorption, driven by entropy in a spontaneous endothermic reaction. Desorption of thorium from the loaded resin ions was effectively accomplished using H 2 SO 4 solution at pH < 2. Additionally, the PCA resin exhibited excellent cycling and regeneration performance, maintaining stability under various acidic conditions and immersion durations. In practical applications, the PCA resin reduced the thorium concentration from 5.5 mg/L to 0.005 mg/L in simulated radioactive wastewater and from 0.56 mg/L to 0.007 mg/L in high-purity LuCl 3 solution, with no measurable loss of rare earths. Characterization through FTIR, Raman and XPS analysis revealed that two oxygen atoms of the –COOH group are bidentate chelating coordination with thorium ions. Furthermore, density functional theory (DFT) calculations provided insights into the selective binding mechanism at the –COOH site, highlighting its role in the effective separation of thorium from rare earths.
CAS / MDL:
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Food Quality and Safety
·
2022
·
IF 3.949
Kang Yuting,Li Chenghua,Li Huiru,Li Jing,Jiang Kezhi
Polycarboxylic acids (PACs) are important metabolic products in almost all living bodies, yet current analytical methods for detection of PACs in tea beverages are still unsatisfactory due to the complex matrix and physicochemical properties of PACs. In this work, a rapid method was developed for the simultaneous determination of 7 PACs, including tartaric acid, α-ketoglutaric acid, malic acid, malonic acid, cis-aconitic acid, succinic acid, and fumaric acid, in beverages, based on selective removal of the matrix in combination with liquid chromatography–mass spectrometry (LC-MS) analysis. By stirring with activated carbon and the Na2CO3 solution, the matrix in beverages was selectively removed, and PACs were almost retained in the supernatant of diluted Na2CO3 solution. Under optimized parameters, the limit of quantitation for the PACs was in the range of 1–50 ng/mL, and the content of the PACs in 8 beverages was determined with the recovery range of 72.2%–122.5%. The contents of malic acid, malonic acid, and succinic acid in tea beverages were found to be greater than those in non-tea beverages. Moreover, the concentration of these PACs in beverages was found to be multiplied many times in their deterioration period, especially for fumaric acid and α-ketoglutaric acid. These results indicated that PACs can be selected as a criterion to differentiate qualified tea beverages from spoiled beverages.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL SCIENCES
·
2018
·Vol. 130
·期 1
·1-11
·
IF 1.254
Lin Hongyan,Lin Jiafeng,Zhao Jing,Tian Yuan,Wang Xiang,Liu Guocheng
Abstract Three new cadmium(II) coordination compounds \([\hbox {Cd}_{2} (\hbox {L})_{2} (\hbox {btec}) (\hbox {H}_{2} \hbox {O})_{2}] \cdot \hbox {3H}_{2} \hbox {O}\) ( 1 ), [Cd(HL)(btb)] ( 2 ) and \([\hbox {Cd}(\hbox {L})(\hbox {pda})] \cdot \hbox {2H}_{2} \hbox {O}\) ( 3 ) were prepared by hydrothermal reactions of cadmium(II) chloride with ligands L ( \(\hbox {L} = \hbox {N}\) , \(\hbox {N}^{\prime }\) -bis(3-pyridyl)octandiamide) in the presence of different aromatic polycarboxylates ( \(\hbox {H}_{4} \hbox {btec} = \hbox {1,2,4,5-benzenetetracarboxylic acid}\) , \(\hbox {H}_{3} \hbox {btb} = \hbox {1,3,5-tri(4-carboxylphenyl)benzene}\) , \(\hbox {H}_{2} \hbox {pda} = \hbox {1,4-phenylenediacetic acid}\) ). The structures of compounds 1 – 3 have been determined by X-ray single crystal diffraction analyses and further characterized by infrared spectroscopy (IR), powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Compound 1 displays a 3D metal-organic framework with (4,4,4)-connected \(\{6^{2}.8^{4}\} \{6^{3}.8^{3}\} \{6^{4}.8^{2}\}\) topology constructed from 2D \([\hbox {Cd}_{2} (\hbox {btec})]_{\mathrm{n}}\) layers and \(\mu _{2}\) -bridging L ligands. Compound 2 is a 3D (3,3)-connected \(\{10^{3}\}\) topological network based on the 3D \([\hbox {Cd(btb)}]_{\mathrm{n}}^{\mathrm{n}-}\) framework and the protonated monodentate HL ligand. Compound 3 shows a 2D layer with (3,5)-connected \((4^{2} \cdot 6^{7} \cdot 8)(4^{2} \cdot 6)\) topological structure, which are further linked by hydrogen bonding interactions to form a 3D supramolecular network. The influences of three aromatic polycarboxylates on the structures of title compounds are investigated. Further, the fluorescent properties of three cadmium(II) compounds and their fluorescent sensing properties towards small solvent molecules and metal cations have been studied.
Graphical Abstract
Three new Cd(II) coordination compounds based on the flexible bis(pyridyl)-bis(amide) ligand and three different polycarboxylates have been hydrothermally synthesized. The polycarboxylates with diverse carboxyl groups and various structures play an important role in constructing three Cd(II) compounds. The thermal stabilities, fluorescent and fluorescence sensing properties of the three Cd(II) compounds towards small solvent molecules and metal cations have been reported.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2019
·
IF 2.12
Yu Yang,Jiang-Yu Bian,Yu-Han Li,Hui-Chao Guan,Yan-Ru Tang,Yan-Ling Chen,Shu-Mei Yue
Six complexes including [Cd (bpt)(odc) 2 ] (1), [Ni(bpt)(odc) 2 ] (2), [Zn (bpt)(odc) 2 ] (3), [Zn (bpt)(1,4-ndc) 2 (H 2 O)] (4), [Cd (bpt)(1,4-ndc) 2 ] (5), [Cd (bpt)(Pta) 2 (H 2 O) 2 ] (6), {bpt = 2-(2 pyridyl)benzothiazole, H 2 odc = 4,4′-oxybisbenzoic acid, 1,4-H 2 ndc = naphthalene-1,4-dicarboxylic acid, Pta = terephthalic acid}, have been determined by single-crystal X-ray diffraction analysis, which shows that complexes 1–3 belong to monoclinic system with space group P2 1 /n, complex 4 and complex 6 belong to triclinic system with space group P-1, complex 5 belongs to monoclinic system with space group P2 1 /c. TD-DFT calculations for the complexes 3 was performed to explain the structures and electronic spectral properties. UV spectroscopy , fluorescence spectroscopy and viscosity were used to characterize the interaction of the CT-DNA complexes. The results indicate that complexes 1–6 have strong interaction with CT-DNA binding. All complexes exhibit an electrostatic or groove mode of binding with DNA . Furthermore, they also present that all complexes have strong ability to interact with DNA. It can effectively destroy the DNA acting on cancer cells. Therefore, we hope to provide a theoretical and scientific basis for the development of anti-cancer drugs.
研究领域:
化学
·
生物化学
·
药学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Xiao-Lan Tong,Qiao-Lin Luo,Jian-Hua Xin,Shu-Juan Liu,Fen Liu,Jian-Hua Ding,Chen Xiong,Min Li,Jian-Qiang Luo,Jian-Bo Xiong
One novel uranyl carboxylate complex [(UO 2 ) ( L) ·2H 2 O] ( 1 ) (H 2 L =4-carboxymethoxy-benzoic acid) was synthesized under hydrothermal conditions by the reaction of UO 2 (NO 3 ) 2 ·6H 2 O and H 2 L in aqueous system. X-ray analysis of single crystal structure determined that complex 1 exhibits one-dimensional ribbon structure, in which, the UO 2 2+ ions are bridged by L 2− . The one-dimensional chains are further connected into 3D supramolecular network by O H…O hydrogen bond interactions between the coordinated water molecule and the coordinated carboxylic oxygen. The π…π interactions between adjacent benzene rings also contribute the structure formation. Complex 1 exhibits emblematic charge-transfer green emission of uranyl-bearing complexes. The UV–vis absorption spectra reveal distinct light absorption both on the ultraviolet and visible regions for 1 . Photocatalytic degradation of rhodamine B (RhB) in aqueous solutions using Complex 1 was studied, 78.3% of the RhB was degraded in only 80 min. Our obtained uranyl coordination polymer represents effective RhB photocatalytic degradation materials in aqueous solution. Infrared spectroscopy, TGA and PXRD were also discussed.
研究领域:
无机化学
·
材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2017
·Vol. 147
·期 6
·1347-1354
·
IF 2.799
Huang Wei,Tao Duan-Jian,Chen Feng-Feng,Hui Wei,Zhu Jia,Zhou Yan
Abstract A new series of aminopolycarboxylate ionic liquids were designed, synthesized, and applied for efficient and selective synthesis of ditetrahydrofurfuryl carbonate (DTC). Tetraethylammonium nitrilotriacetate ([N 2222 ] 3 [NTA]) was demonstrated to show the best catalytic performance, in which DTC could be obtained at a yield of 80% under optimum conditions. Graphical Abstract
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Zi-Ye Liu,Qian-Yu Wang,Teng Xu,Ji-Ming Hu
Nickel–iron layered double hydroxide (NiFe LDH) shows great performance in the oxygen evolution reaction (OER) due to the interaction between Ni and Fe. However, such an interaction still remains insufficient to achieve lower overpotential. To address this, we employ conjugated polycarboxylate ligands to promote electron transfer between Ni and Fe in NiFe LDH. This results in the formation of high-valence Ni in NiFe LDH, and also strengthens the adsorption of O intermediates at Ni sites. In this study, oxalate and 1,3,5-benzenetricarboxylate (BTC) are used to modify NiFe LDH, synthesized via the gas–solid reaction method and the decomposition of MIL-100(Fe) method, respectively. Oxalate-modified NiFe LDH has a low overpotential of 238 mV and Tafel slope of 38.1 mV dec−1, while BTC-modified NiFe LDH is 230 mV and 36.1 mV dec−1. In addition, both of them can work stably for over 24 h at a current density of 100 mA cm−2. The conjugated polycarboxylate ligand modification method is a new strategy to promote the OER performance and extend long-term stability of NiFe LDH.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Ziyun Xu,Shiqi Weng,Chenhui Li,Ming Jin,Decheng Wan
Aminopolycarboxylic acids (APAs) show a strong affinity toward heavy metal species, but straightforward and robust studies on the surface of porous adsorbents with APAs are rarely available. In this study, branched polyethyleneimine (PEI) is directly used to investigate the surface of a microcrystalline cellulose (MC)-supported porous monolith (MC@PEI) through an oil-in-water high internal phase emulsion technique. The residual amines of the covalently immobilized PEI are transformed into dense APAs (MC@PEI-APA). The open-cellular MC@PEI-APA monolith can effectively eliminate trace Cu(II) or Zn(II) from water relative to MC@PEI. Moreover, its adsorption complies with the second-order kinetics and follows the Langmuir adsorption model. MC@PEI-APA shows high adsorption capacities (e.g., 96 mg g −1 for Cu(II)). It also presents stronger metal affinities than the commercial Amberlite IRC-748 adsorbent possibly because of the cooperative ligation of metal species by the relatively dense APA groups of MC@PEI-APA. The proposed adsorbent is durable and has good recyclability.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）