Journal of Energy Chemistry
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2015
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IF 2.352
Wenfei Hu,Yan Zhang,Yizheng Huang,Jiaxi Wang,Jin Gao,Jie Xu
Glycerol can be obtained as a by-product during biodiesel manufacture. It is important to convert glycerol to value-added products. Glycerol esterification with acetic acid is one of the most promising approaches for glycerol utilization. It is usually difficult to obtain diacetin with good activity and selectivity. In this work, glycerol esterification with acetic acid over different metal oxides , such as Bi 2 O 3 , Sb 2 O 3 , SnO 2 , TiO 2 , Nb 2 O 5 and Sb 2 O 5 , was investigated. It was found that in the six investigated metal oxides, only Sb 2 O 5 resulted in good activity and selectivity to diacetin. Under the optimized conditions, the glycerol conversion reached 96.8%, and the selectivity to diacetin reached 54.2%, while the selectivity to monoacetin and triacetin was 33.2% and 12.6%, respectively. The catalysts were characterized with FT-IR spectra of adsorbed pyridine , which indicated that in the six investigated metal oxides, only Sb 2 O 5 possessed Brønsted acid sites strong enough to protonate adsorbed pyridine. The good catalytic activity and selectivity to diacetin might be mainly attributable to the Brønsted acid sites of Sb 2 O 5 . Reusability tests showed that with Sb 2 O 5 as catalyst, after six reaction cycles, no significant change in the glycerol conversion and the selectivity to diacetin was observed.
研究领域:
化学工程
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催化剂科学
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DOI
高影响因子
Journal of Cleaner Production
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2024
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IF 9.7
Jiahui Zhang,Wenliang Zhang,Yue Wang,Shaoyi Jiang,Yan Wang,Zhezheng Ding,Xiaomin Liu
2,4-dichlorophenoxyacetic (2,4-D) acid and 4-chlorophenoxyacetic acid (4-CPA), as widely utilized organochlorine pesticides , are normally detected in wastewater and atmosphere. Their harmfulness to the ecosystem cannot be ignored. UV/H 2 O 2 is one of the most conventional advanced oxidation processes, which has remarkable advantages for the removal of refractory organic pollutants in wastewater. However, the reaction mechanisms and pathways of pollutants with reactive radicals are still unclear. In this study, the degradation efficacy and mechanisms during the photodegradation of 2,4-D and 4-CPA in UV/H 2 O 2 processes were investigated by experiments and density functional theory calculations. The results showed that 2,4-D was more likely to be degraded by UV/H 2 O 2 treatment than UV photolysis alone. In contrast, 4-CPA can be degraded effectively and rapidly under UV irradiation alone. By LC-MS analysis, the degradation products of 2,4-D and 4-CPA in the UV/H 2 O 2 processes were identified and they were produced by hydroxylation and photolysis. Therefore, we speculated a competition mechanism presented between direct photolysis and indirect photolysis in the UV/H 2 O 2 degradation of 2,4-D and 4-CPA. The OH-initiated reaction mechanisms of 2,4-D and 4-CPA in aqueous environments were investigated using quantum chemical methods SMD/M06–2X/6–311++G (3df, 2p)//SMD/M06–2X/6-311 + G (d,p). The pH dependence of the reaction mechanisms and rate constants in their degradation process induced by ·OH was also investigated. The calculation results showed that the ionic forms (2,4-D - and 4-CPA - ) were more prone to react with ·OH in comparison to the corresponding molecular forms (2,4-D and 4-CPA). The total rate constants of 2,4-D and 4-CPA with OH increased with the pH from 1 to 10, and decreased with continued pH increase. The toxicities of 2,4-D, 4-CPA and their products were assessed by the QSAR-based toxicity evaluation software. The results showed that several products were more toxic than their parent compounds, such as 2,4-dichlorophenol, 3,5-dichlorocatechol, 4-chlorophenol and hydroquinone . This work can contribute to clarifying the environmental risks of 2,4-D and 4-CPA and offer a complete understanding for the photodegradation behavior of 2,4-D and 4-CPA in aqueous ecosystems.
研究领域:
环境科学
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化学
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DOI
高影响因子
CRYSTENGCOMM
·
2024
·
IF 2.6
Hao He,Xiao-kai Liu,Bai-yun Zhao,Li-juan Zhou,Xuan Zhao,Chen-xu Wang,Ji-yuan Zhang,Yuan-fang Zhang,Li Wang
In this study, UiO-66-NH2 nanoparticles were synthesized via a hydrothermal method, using acetic acid and hydrochloric acid as modulators to optimize the specific surface area and pore width. Oxytetracycline (OTC) was chosen as the test compound to evaluate the adsorption efficiency of UiO-66-NH2.The material was thoroughly characterized under varying conditions, and the adsorption mechanism was systematically explored through adsorption kinetics, isotherms, and thermodynamic analyses. The results demonstrated that UiO-66-NH2 exhibited a high OTC adsorption capacity, achieving a maximum of 312.5 mg g−1 under optimal conditions. XRD, TGA, and BET analyses revealed that acetic acid and hydrochloric acid significantly improved the crystallinity and thermal stability of UiO-66-NH2, increasing the specific surface area from 8.023 m2 g−1 to 998.663 m2 g−1 and reducing the pore width from 18.783 nm to 2.129 nm. FTIR, XPS, adsorption kinetics, and isotherm studies indicated that the main forces driving OTC adsorption by CMC-Fe were hydrogen bonding, π–π stacking, weak electrostatic interactions, and pore filling. Cyclic adsorption experiments further demonstrated the excellent reusability of UiO-66-NH2. In summary, the use of acetic acid and hydrochloric acid significantly increased the specific surface area of UiO-66-NH2, exposing more adsorption sites and playing a critical role in pollutant removal.
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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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2022
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IF 8.129
Huiyan Zhang,Chenjun Yang,Yujie Tao,Min Chen,Rui Xiao
The unstable oxygenates of raw bio-oil limit its high-value utilization, which renders the refinement process necessary. Catalytic cracking is one of the promising refining methods and HZSM-5 was found to be an effective catalyst. To investigate the reaction mechanism of catalytic cracking of the oxygenated components in bio-oil, guaiacol and acetic acid, are employed for the catalytic conversion over HZSM-5 and metal modified zeolite Zn/HZSM-5 in a self-designed micro-reactor. Herein, the mechanism of pyrolysis and catalytic cracking was calculated by density functional theory (DFT). For guaiacol, the selectivity of salicylaldehyde decreased from 57.41% to 41.84% and 40.31% over HZSM-5 and Zn/HZSM-5, respectively. In the catalytic cracking over Zn/HZSM-5, the yield of aromatic hydrocarbon increased. More specifically, benzene appeared in the liquid product. For acetic acid, the removal of the oxy-functional group was further promoted by Zn/HZSM-5, the as-formed ketene intermediate continues to react with zeolite catalysts, generating acetyl cation, and finally formed CO and ethylene. Zn/HZSM-5 has a better effect on promoting the reaction of ketene and methoxide since the energy barrier of the rate-determining step in this reaction decreased from 163.27 kJ/mol to 151.19 kJ/mol. Demethoxylation and dehydration were considered to be favored by Lewis acid sites.
研究领域:
化学工程
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能源科学
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DOI
高影响因子
Insects
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2025
·Vol. 16
·期 2
·111
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IF 2.9
Liuyang Wang,Yubo Wang,Xiaofang Zhang,Meijuan Fang,Xiangdong Mei,Tao Zhang
Simple SummaryPlant bugs’ locating of mates mainly relies on peculiar chemical signals known as sex pheromones, which can be utilized to develop environmentally friendly pest control methods. This study investigated the sex pheromones ofPolymerus pekinensis, a phytophagous insect of alfalfa crops in East Asia. By analyzing chemical extracts from both male and female insects, we identified two antenna-active compounds: octyl acetate (OA) and decyl acetate (DA). Females produced higher amounts of OA, while males produced greater quantities of DA. Field experiments demonstrated that lures loaded with solely OA strongly attracted maleP. pekinensis, making it a valuable tool for monitoring this pest. However, the addition of DA in larger amounts significantly decreased the attractivity of lures. Our findings offer new strategies for monitoring and managing these insects in a manner that does not harm non-target insects.Insect sex pheromones have been widely used in integrated pest control due to their efficiency, non-toxicity, specificity, and environmental sustainability. They are considered a key component of green pest management techniques.Polymerus pekinensisis a phytophagous plant bug on alfalfa (Medicago sativaL.) in East Asia. This study used gas chromatography–electroantennogram detection (GC–EAD) and gas chromatography–mass spectrometry (GC–MS) to analyze the whole-body extracts from male and femaleP. pekinensis. Octyl acetate (OA) and decyl acetate (DA) elicited the antennal response of males and were identified as the predominant components of female and male extracts, respectively. Subsequent field trials demonstrated that OA (>8 mg per lure) showed the strongest attraction to conspecific males. However, when DA was added in a lure (≥2 mg), a significant decline in captures occurred. These findings provide new insights into the understanding of sex pheromones in Miridae and benefit the development of sustainable management ofP. pekinensis.
研究领域:
昆虫学
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农业科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2014
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IF 2.045
Fuqiong Lei,Qinbo Wang,Xing Gong,Binwei Shen,Wenming Zhang,Qing Han
The solubilities of succinic acid in acetic acid + water solvent mixtures at (303.2 to 333.2) K and acetic acid + cyclohexane solvent mixtures at (303.2 to 343.2) K were determined. It was found that the solubility of succinic acid in acetic acid + cyclohexane mixtures increases with increasing mass fraction of acetic acid at constant temperature. However, for the system of acetic acid + water solvent mixtures, acetic acid with the mass fraction of 0.20 shows the best dissolving capacity for succinic acid. The experimental data were well-correlated with universal quasi-chemical (UNIQUAC) equations, and the solubilities calculated by the model were in good agreement with experimental data.
研究领域:
物理化学
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材料科学
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
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2018
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IF 4.946
Hossein Mohammadzadeh-Aghdash,Yousef Sohrabi,Ali Mohammadi,Dariush Shanehbandi,Parvin Dehghan,Jafar Ezzati Nazhad Dolatabadi
Cytotoxicity and genotoxicity of sodium acetate (SA), sodium diacetate (SDA), and potassium sorbate (PS) was tested on Human Umbilical Vein Endothelial Cells (HUVEC). Cytotoxicity was investigated by MTT assay and flow cytometry analysis, while genotoxicity was evaluated using DNA fragmentation and DAPI staining assays. The growth of treated HUVECs with various concentrations of SA , SDA and PS decreased in a dose-and time-dependent manner. The IC50 of 487.71, 485.82 and 659.96 µM after 24 h and IC50 of 232.05, 190.19 and 123.95 µM after 48 h of treatment were attained for SA, SDA and PS, respectively. Flow cytometry analysis showed that early and late apoptosis percentage in treated cells was not considerable. Also neither considerable DNA fragmentation nor DNA smear was observed using DAPI staining and DNA ladder assays. Overall, it can be concluded that the aforementioned food additives can be used as safe additives at low concentration in food industry.
研究领域:
毒理学
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食品科学
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细胞生物学
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DOI
PubMed
高影响因子
JOURNAL OF FOOD SCIENCE
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2021
·Vol. 86
·期 12
·5495-5502
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IF 3.167
Liangting Shao,Yue Qin,Xinglian Xu,Huhu Wang
Sodium hypochlorite (NaClO) has been widely used at 100 ppm concentration during poultry slaughter to reduce carcass microorganism loads. However, its use in poultry processing is restricted owing to the potential risks of disinfection by-products (DBPs) that can be produced by the reaction of NaClO with poultry meat components. This study assessed whether dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), as primary DBP representatives, were produced when NaClO was used as a disinfectant in various methods during broiler prechilling. Headspace gas chromatography-mass spectrometry for the quantitative determination of DCAA and TCAA in 180 prechilling water samples and 30 broiler meat samples, obtained from large standard slaughterhouses equipped with an online monitoring system to control the NaClO concentration between 50 and 100 ppm, showed that neither DCAA nor TCAA were detected. In simulation assays, haloacetic acids (HAAs) were not detected when the concentration of the NaClO solution was less than 200 ppm with low frequency addition; however, more than 0.1 mg/L of DCAA and TCAA were detected on applying 200, 300, 400, 500, and 1000 ppm NaClO at high frequency. These findings indicated that adding high concentrations of NaClO and frequently adding low levels pose a potential risk of DBP formation. This investigation provides a basis for the establishment of food risk and the scientific use of NaClO in poultry processing, and contributes to the evaluation of DBPs in poultry slaughter. Practical Application This study confirmed the occurrences of DCAA and TCAA during broiler chilling processing, indicating that formation of HAAs in simulation systems was correlated with NaClO levels and validated the absence of DCAA and TCAA with less than 200 ppm, providing a basic study for food safety standards and regulations on the disinfectants used in food processing.
研究领域:
食品安全
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环境科学
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食品科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2011
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IF 2.733
Ying Hua Xu,Hong Zhang,Cheng Pu Chu,Chun An Ma
Chloroacetic acids (CAAs, including trichloroacetic acid, dichloroacetic acid and monochloroacetic acid) are byproducts formed upon the addition of chlorine to water for disinfection purpose and they pose a potential human health risk. To catalyze the dechlorination of CAAs, an activated silver electrode was prepared by an oxidation–reduction cycle process. Surface structure and roughness factor of the activated silver electrode and its catalytic activity (including stability) towards the dechlorination of CAAs in aqueous solutions of different pH were studied by SEM, underpotential deposition (UPD) method, cyclic voltammetry (CV) and controlled-current electrolysis, respectively. Experimental evidence is presented that the activated silver electrode, having a porous surface with a roughness factor of approx. 63.9, is an excellent electrocatalytic material for direct dechlorination of CAAs and the complete dechlorination of trichloroacetic acid to safe acetic acid with excellent current efficiency (near 95%) can be successfully achieved by using this peculiar electrode in alkaline aqueous solutions. The reduction of trichloroacetic acid in a stepwise dechlorination fashion was suggested and trichloroacetic acid (TCAA) → dichloroacetic acid (DCAA) → monochloroacetic acid (MCAA) → acetic acid (AA) probably is the main reductive reaction route independent of pH.
研究领域:
环境科学
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电化学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
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2019
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IF 0.67
He Li,Yijun Zhang,Dinghua Liu,Xiaoqin Liu
2,4-Dichlorophenylacetic acid is synthesized in high yield via the carbonylation of 2,4-dichlorobenzyl chloride, and various experimental conditions are evaluated. Xylene, bistriphenylphosphine palladium dichloride, tetraethylammonium chloride and sodium hydroxide in solution are added to the reaction system and held at 80 °C under a CO atmosphere. 2,4-Dichlorophenylacetic acid is obtained in a maximum yield of 95%, and a mechanism for 2,4-dichlorobenzyl chloride carbonylation is proposed. The reaction system provides a mild, effective and novel means by which to prepare phenylacetic acid derivatives from their corresponding benzyl chloride derivatives.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
CELLULOSE
·
2017
·Vol. 25
·期 1
·205-216
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IF 3.417
Xu Qinqin,Song Longchu,Zhang Lihua,Hu Gang,Chen Qin,Liu Enhui,Liu Yu,Zheng Qiang,Xie Haibo,Li Nanwen
The reversible reaction of the hydroxyl groups in cellulose with CO 2 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) results in a rapid and effective derivative dissolution of cellulose in DMSO, by which a series of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) with various degrees of substitution (DS) were synthesized controllably without adding external catalysts. Wherein DBU not only achieves the dissolution of cellulose, but also acts as an efficient organocatalyst for the subsequent cellulose derivatization. The DS of CAB and CAP can be tuned by changing the feed molar ratio of propionic (butyric) anhydride/acetic anhydride and the reaction temperature. The structural and thermal properties of the products were characterized by several analytical techniques including NMR, FT-IR, and TGA. The CO 2 /DBU/DMSO dissolution system provides a new platform for controllable synthesis of mixed cellulose esters with high efficiency under mild conditions.
研究领域:
材料科学
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有机化学
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产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
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2015
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IF 2.2
Zhixian Huang,Ling Li,Miaomiao Zhou,Haiming Jiang,Ting Qiu
Vapor–liquid equilibrium data for ethyl trifluoroacetate + trifluoroacetic acid , ethyl trifluoroacetate + ethanol, and trifluoroacetic acid + water at the pressure 101.3 kPa were measured with a modified Rose still. The thermodynamic consistency of the VLE data was confirmed by Herrington’s method. The VLE data were correlated by the NRTL and Wilson models with satisfactory results, and the interaction parameters of these mixtures were estimated.
研究领域:
化学工程
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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）