INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Siyuan Zhao,Ke Ma,Kailong He,Xiaoxun Ma,Chengyi Dai
Due to cost and energy consumption constraints, converting benzene into ethylbenzene using low-cost syngas instead of ethylene as an alkylation reagent is significant. However, when using syngas as the reaction raw material, generating ethylated side chains on the benzene ring is challenging. Instead, toluene/xylene becomes the primary product. We used a three-bed series connection method in a reactor, achieving one-step high selectivity of syngas and benzene to produce ethylbenzene. In the first bed layer (ZnAl2O4/SAPO-34), the syngas was first converted into methanol/dimethyl ether (DME) on ZnAl2O4. Then, it was further converted into low-carbon olefins on SAPO-34, with the microporous shape-selective effect of SAPO-34, inhibiting the generation of toluene/xylene in the alkylation of benzene with methanol/DME. At the same time, we proved that the absence of microporous shape-selective effect acid sites on the outer surface of S34 can lead to the occurrence of side reactions of benzene and methanol/DME methylation. In the second bed layer, SAPO-34 could continue to convert unconverted methanol/DME in the first bed layer into low-carbon olefins. In the third layer (ZSM-5), ethylene and benzene underwent highly selective alkylation on ZSM-5 to convert it into ethylbenzene. We found a “volcanic” curve relationship between the selectivity of ethylbenzene and the Brønsted acid site density of ZSM-5. On the one hand, Brønsted acid could catalyze the formation of ethylbenzene from benzene and ethylene; On the other hand, excessive Brønsted acid could lead to the isomerization of ethylbenzene to toluene/xylene. When the Brønsted acid showed a site density of 0.7 mmol/g, the selectivity of ethylbenzene was as high as 87%, with a byproduct of xylene showing only 0.3%, which is usually difficult to separate from ethylbenzene. Finally, the three-bed catalytic system showed no deactivation after 100 h.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2024
·
IF 2.8
Yan Jiaqi,Chen Gui,Lu Sihang,Wang Pin,Hu Zhengwu,Chen Wenkai,Yuan Ye
In this work, a stable bimetallic hydrotalcite-derived NiCu/MgAlO catalyst and O 2 as oxidant were used for the toluene oxidation to produce the valuable benzyl alcohol (PhCH 2 OH) and benzaldehyde (PhCHO) under solvent-free and additive-free conditions. This strategy gave 7.2% toluene conversion with 70.7% selectivity to PhCH 2 OH & PhCHO. Multiple characterizations showed that highly dispersed metallic Cu and Ni were anchored on the support surface and a chemical bonding interaction occurred between the metallic Ni and the MgAlO. The metal–support interaction contributed to the formation of active Ni 0 species and NiCu alloy with abundant oxygen defects, resulting in excellent catalytic activity and acceptable stability. A plausible reaction mechanism for the catalytic oxidation of toluene over NiCu/MgAlO catalyst has been proposed. The attractive feature of the present catalytic oxidation system compared to conventional methods was its ability to achieve high selectivity for the desired target product. The further advantage of NiCu/MgAlO catalyzed toluene oxidation was that the reaction temperature and time could be below 180 °C and 2 h, thereby minimizing energy consumption and reducing effluent wastewater, which has potential application prospects.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING COMMUNICATIONS
·
2023
·
IF 2.5
Yilin Zhao,Nengcheng Zhou,Min Hua,Xiuxia Guo,Wenxing Zhang,Huichun Jiang,Xuhai Pan,Juncheng Jiang
In this article, the thermal stability of tert-butyl perbenzoate (TBPB) mixed with different concentrations of toluene and p-tert-butylcatechol (TBC) was investigated. The exothermic onset temperature (T0), the heat of decomposition (ΔH), and the adiabatic temperature rise (ΔTad) of the samples were obtained by differential scanning calorimetry (DSC) and Phi-TEC II adiabatic calorimetry. The apparent activation energy (Ea) and the maximum reaction rate arrival time under adiabatic conditions were obtained by adiabatic kinetic calculations for 8 h (TD8) and 24 h (TD24). Based on Semenov’s theory, the self-accelerated decomposition temperature was calculated as a support for safe storage and transport. The results of DSC and Phi-TEC II showed that toluene was effective in reducing the thermal hazard during the decomposition of TBPB. The addition of TBC caused side reactions. The moderate addition of toluene and TBC improves the thermal stability of TBPB and can improve the safety of TBPB in industrial applications.
研究领域:
化学工程
·
安全科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 39
·e54455
·
IF 3
Wenjie Feng,Jiadeng Zhu,Chen Yang,Wentao Li,Mengjin Jiang
Poly-p-phenylene-(1,3,4-oxadiazole) (POD) fibers have attracted tremendous attention due to the excellent thermal stability, however, their poor ultraviolet (UV) resistance seriously restricted the application. Some efforts have been devoted to improving the UV stability of POD, while the methods are generally too complicated or costly. This work applied a simple but effective approach to obtain POD/PPTA composite fibers by blending poly-p-phenylene terephthamide (PPTA) with POD. The results showed that the obtained POD/PPTA composite fibers exhibited enhanced tensile strength and heat resistance compared to the pure POD fibers. The POD/10%PPTA composite fibers retained 68% strength and 43% elongation even after 24 h UV accelerated aging. The improvement of UV resistance was attributed to the photoinduced electron transfer reaction in POD/PPTA composite fibers, which has been demonstrated by both experimental and simulation studies.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Qing-Shuai Zhang,Yu-Le Wang,Li Yue,Yu-Dong Shan,Song-Hai Wu,Yong Liu,Xu Han
Although selective oxidation of benzene to phenol (SOBP) by H2O2 is an important chemical process, overoxidation of benzene by the produced nonselective •OH during the activation of H2O2 inevitably reduces the oxidation selectivity. We, therefore, attempt to mediate the oxidation selectively by using electrophilic KHCO3 in the oxidation system. In this study, Mo–Cu/NC has been successfully synthesized via ball-milling bimetallic Mo–Cu and N-doped carbon, which exhibits high reactivity in SOBP by H2O2 and KHCO3 with a desirable phenol yield of 25.1% and selectivity of 100%. A series of characterizations and DFT calculations reveal that the reaction between H2O2 and KHCO3 produces HCO4–, which is then moderately activated on Mo1Cu2/NC via the nonradical pathway with the formation of Mo-(η2-O2) peroxo. Meanwhile, Ov at Mo1Cu2/NC facilitates the adsorption of benzene, which is then selectively oxidized by Mo-(η2-O2) peroxo to phenol via the oxygen atom transfer pathway. This study provides new insights on the importance of Mo-(η2-O2) peroxo mediated by H2O2–KHCO3 in selective oxidation of aromatic C–H bond via the nonradical pathway.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICO-BIOLOGICAL INTERACTIONS
·
2024
·
IF 4.7
Jingyu Wang,Lin Han,Ziyan Liu,Wei Zhang,Lei Zhang,Jiaru Jing,Ai Gao
Benzene is the main environmental pollutant and risk factor of childhood leukemia and chronic benzene poisoning. Benzene exposure leads to hematopoietic stem and progenitor cell (HSPC) dysfunction and abnormal blood cell counts. However, the key regulatory targets and mechanisms of benzene hematotoxicity are unclear. In this study, we constructed a benzene-induced hematopoietic damage mouse model to explore the underlying mechanisms. We identified that Insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) was significantly reduced in benzene-exposed mice. Moreover, targeting IGF2BP1 effectively mitigated damages to hematopoietic function and hematopoietic molecule expression caused by benzene in mice. On the mechanics, by metabolomics and transcriptomics, we discovered that branched-chain amino acid (BCAA) metabolism and fatty acid oxidation were key metabolic pathways, and Branched-chain amino acid transaminase 1 (BCAT1) and Carnitine palmitoyltransferase 1a (CPT1A) were critical metabolic enzymes involved in IGF2BP1-mediated hematopoietic injury process. The expression of the above molecules in the benzene exposure population was also examined and consistent with animal experiments. In conclusion, targeting IGF2BP1 alleviated hematopoietic injury caused by benzene exposure, possibly due to the reprogramming of BCAA metabolism and fatty acid oxidation via BCAT1 and CPT1A metabolic enzymes. IGF2BP1 is a potential regulatory and therapeutic target for benzene hematotoxicity.
研究领域:
毒理学
·
血液学
·
分子生物学
·
代谢组学
·
转录组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Optical Materials
·
2022
·Vol. 11
·期 5
·2202259
·
IF 10.05
Weihua Luo,Yiyuan Tang,Xin Zhang,Zhen Wu,Guojie Wang
It is extremely significant and desirable to integrate the fascinating mechanochromism and photochromism in one simple molecule. Herein, two intriguing cyanostilbene-containing triphenylamine (TPA)/tetraphenylethylene (TPE) derivatives ( Z -TPA-MB and Z -TPE-MB) are elaborately designed, which not only display excellent aggregation-induced emission (AIE) properties with high solid-state fluorescence quantum yields (60.9% and 63.8%) but also exhibit reversible and high contrast mechanochromism and distinct photochromism. The powders of Z -TPA-MB and Z -TPE-MB both exhibit large red-shift under mechanical stimulation based on the highly twisted conformation and the resulting loose packing mode, accompanied by significant changes in apparent and fluorescent colors. Meanwhile, their solid-state fluorescence can be reversibly switched between crystalline and amorphous structures through alternating grinding and solvent fuming, exhibiting good fatigue resistance. In addition, the molecules also exhibit distinct dual-mode photochromic behaviors owing to the presence of cyanostilbene moieties: under 420/365 nm light irradiation, the fluorescence of which decreases in solution owing to the photo-isomerization, while decreases and blue-shifts in the aggregated state owing to the photodimerization reactions. The reversible, tractable, and high-contrast mechanochromism and distinct photochromism of the cyanostilbene-containing molecules endow them with excellent application prospects in the field of rewritable papers and photo-patterning.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2023
·
IF 4.5
Jifang Zhang,Chengcheng Suo,Jinde Sun,Wei Li,Sha Luo,Chunhui Ma,Shouxin Liu
In this study, C α –C β and C β –O bond cleavage of β-O-4 model compound (2-phenoxy-1-phenylethanol) were accomplished by electrocatalysis depolymerization process in deep eutectic solvents (DES) systems. We have investigated the application of Ni-Co/C catalysts on working electrode, which were synthesized with impregnation method. The Ni-Co/C with porous structure and abundant active sites, was shown an excellent electrocatalysis activity. Specific structure of Ni-Co/C could provide greatly efficient adsorption and desorption capacity to promote C α –C β and C β –O bond cleavage. Therefore, in this electrocatalysis depolymerization process, the highest depolymerization rate exceeded 90%. And the yields (and conversion rates) of products (including benzaldehyde, acetophenone, benzoic acid, phenol) can reach to 124.08 mg/g (25.05%), 23.29 mg/g (4.15%), 44.64 mg/g (7.83%), 30.3 mg/g (6.9%). Furthermore, the electrocatalysis mechanism of C α –C β and C β –O bond was investigated. The cleavage of C α –C β and C β –O bond was initiated by in situ generated free radicals through Ni-Co/C. Then, the cleavage of C α –C β and C β –O bond were occurred by ·OH and ·O 2 − . The results were showed that the C α –C β bond cleavage was more in line with the β-C elimination and free radical pathways, and C β –O bond cleavage was consistent with direct oxidative addition. The enhanced electrocatalytic efficiency of the low-cost Ni-Co/C electrocatalyst combined with its good chemical stability and selectivity, which offer a promising route for developing an efficient lignin depolymerization technology.
研究领域:
化学工程
·
材料科学
·
环境化学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
BIODEGRADATION
·
2017
·Vol. 29
·期 1
·1-10
·
IF 2.018
Wang Hui,Hu Jinxing,Xu Kai,Tang Xianjin,Xu Xinhua,Shen Chaofeng
Two biphenyl-degrading bacterial strains, SS1 and SS2, were isolated from polychlorinated biphenyl (PCB)-contaminated soil. They were identified as Rhodococcus ruber and Rhodococcus pyridinivorans based on the 16S rRNA gene sequence, as well as morphological, physiological and biochemical characteristics. SS1 and SS2 exhibited tolerance to 2000 and 3000 mg/L of biphenyl. And they could degrade 83.2 and 71.5% of 1300 mg/L biphenyl within 84 h, respectively. In the case of low-chlorinated PCB congeners, benzoate and 3-chlorobenzoate, the degradation activities of SS1 and SS2 were also significant. In addition, these two strains exhibited chemotactic response toward TCA-cycle intermediates, benzoate, biphenyl and 2-chlorobenzoate. This study indicated that, like the flagellated bacteria, non-flagellated Rhodococcus spp. might actively seek substrates through the process of chemotaxis once the substrates are depleted in their surroundings. Together, these data provide supporting evidence that SS1 and SS2 might be good candidates for restoring biphenyl/PCB-polluted environments.
研究领域:
环境微生物学
·
生物修复
·
微生物生态学
·
趋化性
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ZEITSCHRIFT FUR KRISTALLOGRAPHIE-NEW CRYSTAL STRUCTURES
·
2022
·Vol. 238
·期 1
·13-14
·
IF 0.365
Zhihong Zhu,Lilei Zhang
C 14 H 12 BrClN 2 O, monoclinic, P 2 1 / c (no. 14), a = 13.4072(6) Å, b = 8.6103(5) Å, c = 12.3824(6) Å, β = 100.475(4), V = 1405.60(12) Å 3 , Z = 4, R gt
( F ) = 0.0499, wR ref
( F
2 ) = 0.1215, T = 173 K.
研究领域:
化学
·
晶体学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 25
·25445-25451
·
IF 2.914
Yi Xianliang,Wang Jianfeng,Li Zhaochuan,Zhang Zherui,Chi Tongtong,Guo Miao,Li Wentao,Zhou Hao
The effect of polystyrene (PS) particles on the toxicity of triphenyltin (TPT) to the marine diatom Skeletonema costatum was investigated. The 0.1-μm PS particles attached to the cell walls of S. costatum but did not cause adverse effects on the growth of the diatom. The adsorption of TPT to PS particles was negligible in seawater systems, but the presence of 0.1-μm PS significantly reduced the bioavailable concentrations of TPT in f/2-Si medium, indicating a potential three-way interaction between TPT, PS particles, and components of f/2-Si medium. The adsorption of TPT to PS of smaller size (i.e., 0.1 μm) was stronger than that of PS of larger size (i.e., 5 μm), which was probably attributed to larger surface areas of smaller PS particles. The presence of PS could reduce the toxicity of TPT. IC 50 values of TPT increased from 0.56 to 0.85 and 0.71 μg/L at the presence of 20 mg/L 0.1-μm PS and 5-μm PS, respectively. The overall results of this study profiled the combined toxic effects of PS and TPT on marine phytoplankton species and highlighted the difference in adsorption of organic pollutants by microplastics in different ambient mediums.
研究领域:
海洋生物学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Chemistry
·
2012
·Vol. 9
·期 6
·558-563
·
IF 2.57
Lei Wu,Xuefeng Hu,Lei Wu,Xuefeng Hu
Environmental context Aromatic amines are widely used chemicals, which show enhanced toxicity and longer environmental persistence when halogenated. We investigated the chlorination of aniline in seawater and in natural aqueous solutions containing Fe3+ and Cl–, under simulated sunlight irradiation. The results increase our understanding of the transformation pathway of typical nitrogen-containing aromatic contaminants in the environment. Photochlorination of aniline was observed in aqueous solutions containing dissolved FeIII and chloride ions under simulated solar light irradiation. Effects of O2, Cl–, Fe3+ and pH on the formation of chloroanilines (CAs) were investigated. para-chloroaniline (4CA) was identified as the main chlorinated product. The formation of 4CA is enhanced with increased concentrations of Cl– or Fe3+, and decreased pH, whereas oxygen plays a negligible role in the process. The results indicate that, Cl• is formed mainly by the photodissociation of FeCl2+–FeCl2+ complexes, and reacts with Cl– to produce Cl2•–. Aniline is then oxidised by Cl2•– into an anilino radical cation, which further reacts with Cl2•– to generate CAs. The photochlorination of aniline in natural seawater was also observed. Other phototransformation products of aniline were detected and a transformation pathway was proposed. This work provides evidence for the photochemical chlorination path of aniline-based aromatic amines in aqueous solutions.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
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