RSC Advances
·
2016
·Vol. 6
·期 80
·76707-76715
·
IF 3.289
Bing Yan,Hongjun Zang,Yi Jiang,Songbai Yu,Eugene Y.-X. Chen
Six Na+/montmorillonite (MMT) – supported thiazolium (TM) ionic liquids (ILs), MMT–[TM], which are precatalysts to N-heterocyclic carbene (NHC) catalysts, have been synthesized and employed to catalyze the highly selective condensation of furfural (FF) and 5-hydroxymethylfurfural (HMF) into C10 and C12 furoins, respectively. Among them, five supported [TM] salts carrying the electron-donating group exhibit excellent catalytic activity. Thus, supported NHC catalysts, generated in situ from activation of MMT–[TM] with Et3N, afford C10 and C12 furoins in 97–99% and 97–98% yield, respectively. This condensation reaction is also carried out under solvent-free conditions, and the catalysts can be readily recycled, showing no noticeable loss in their catalytic activity over four consecutive recycles. Thus, these desired features possessed by the current catalyst system have enabled the development of the greener and more environmentally benign process for the upgrading of FF and HMF.
✓ 已验证
DOI
高影响因子
SPECTROSCOPY LETTERS
·
2014
·
IF 0.718
Jing Zhang,Yijin Ren,Fang Chang,Qiuyi Shi
A fixed time point on the curve of the absorbance variation with time determined in the hydroxyl polyaluminum solution by 7-iodine-8-hydroxyquinoline-5-sulfonic acid-timed spectrometry is usually used to quantify the mononuclear aluminum species in the hydroxyl polyaluminum solution. The right choice of the determining time of mononuclear Al must be established on the basis of the sufficient reaction between chromogenic reagent and the hydroxyl polyaluminum solution. But this question has never been noted, which resulted in the confusion of application and research of this assay. In this work, the effect of variation of the determining time on the accurate determination of mononuclear Al in the hydroxyl polyaluminum solution was first studied. The experimental results showed that 60 s was the best under the appropriate dosage of 7-iodine-8-hydroxyquinoline-5-sulfonic acid. The reasonableness of 60 s was further verified by 27Al nuclear magnetic resonance spectrometer and the absorbance–time curve obtained from the pure mononuclear Al solution with pH < 2. The above conclusion was further used to analyze the results reported in literature. The mononuclear Al determined at 60, >60, and <60 s in the literature were comparable to the corresponding results of this study.
✓ 已验证
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2014
·
IF 8.535
Na Lu,Wei Chen,Guoyong Fang,Bi Chen,Keqin Yang,Yun Yang,Zhencai Wang,Shaoming Huang,Yadong Li
We report that 5-fold twinned nanowires and single twinned right bipyramids of Pd with high yields can be selectively synthesized in a hydrophilic system with the assistance of acetonitrile and ethanol, respectively. The controlled synthesis is based on an idea that small organic molecules (SOMs) that can attract halide ions via electrostatic interactions of different strengths could well adjust their activity to tune the etching degree of O2/halides for protecting the twinned Pd crystal nucleus. We consider that relatively stronger interaction between acetonitrile and halide ions for the formation of nanowires is due to the existence of three C–Hδ+ bonds induced by the electron-withdrawing CN group of CH3CN, which is confirmed by an as-called iodine starch test, 1H nuclear magnetic resonance spectra, and theoretical calculations. On the basis of this finding, we then have successfully expanded SOMs to other molecules, including acetone, 1,4-dioxane, and 1,3,5-trioxane, which have a function similar to that of acetonitrile for the production of Pd nanowires, and 2-propanol, which has a function similar to that of ethanol for the fabrication of right bipyramids. Although nanowires and bipyramids are both mainly bound by {001} planes, nanowires show better catalytic performance toward the reduction of 4-nitrophenol, indicating that more twin boundaries could offer more active catalytic sites. This work not only provides new information to decrease the degree of etching of O2/halides for controlling twin structure of noble metals but also supports the idea that creating a twin structure is good for enhancing catalytic activity.
✓ 已验证
产品关联
DOI
高影响因子
Forensic Toxicology
·
2014
·Vol. 32
·期 2
·331-337
·
IF 5.756
Wurita Amin,Hasegawa Koutaro,Minakata Kayoko,Watanabe Kanako,Suzuki Osamu
Traffic police brought five dubious herbal product packages to our laboratory for toxicological analysis. These products usually contain one or multiple kinds of synthetic cannabinoids. In one of the packages, we identified the coexistence of a new type of dubious drug (diphenidine) with the synthetic cannabinoid 5-fluoro-AB-PINACA. Conclusive identification was performed by comparison of the mass spectra of the test herb extracts with those of the reference standards of diphenidine and 5-fluoro-AB-PINACA by both gas chromatography–mass spectrometry (GC–MS) and electrospray ionization–tandem mass spectrometry. Both mass spectra of the test extracts coincided with those of the reference standards for each MS method. Diphenidine and 5-fluoro-AB-PINACA were quantitated in the herbal product by GC–MS using selected ion monitoring and the standard addition method. The content of diphenidine in the herbal product was as high as 289 ± 23.2 mg/g ( n = 5); that of 5-fluoro-AB-PINACA was 55.5 ± 5.8 mg/g ( n = 3). Diphenidine is known as an N -methyl- d -aspartate receptor channel blocker. Although its human toxicity has not been studied, it is likely to have severe psychotropic action in humans. The very high content of diphenidine in the present herbal package should prompt law enforcement agencies to be aware of the potential harmful effects of diphenidine itself and also when consumed in combination with other drugs of abuse.
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 103
·59175-59184
·
IF 3.708
Jianming Pan,Heping Gao,Yunlei Zhang,Jun Zeng,Weidong Shi,Changhua Song,Yongsheng Yan,Longbao Yu,Dandan Chang
This work addressed efficient one-pot conversion of cellulose to 5-hydroxymethylfurfural by porous solid acid in the presence of 1-ethyl-3-methyl-imidazolium chloride ([Emim]Cl). On the basis of stable water-in-oil pickering high internal phase emulsions (HIPEs), porous solid acid (HC-PDVB-SS-SO3H) was prepared by polymerizing divinylbenzene (DVB) and sodium p-styrenesulfonate (SS), succedent sulfonation in H2SO4 and hypercrosslinking process. HC-PDVB-SS-SO3H with a stable network exhibited mesopores within a macropore structure, high BET specific surface area and more super-strong acid sites. To test catalytic activity, the reaction conditions were optimized via response surface methodology, and the sequence of the three variables affecting HMF yield followed the order, temperature > reaction time > amount of catalyst. By comparing with the other as-prepared porous solid acid, it can also be concluded that BET specific surface area and super-strong acid site both played key roles in cellulose conversion. Moreover, HC-PDVB-SS-SO3H was very easily reused at least four times without significant loss of activity.
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Huiyan Zhang,Shanshan Shao,Mengmeng Luo,Rui Xiao
Catalyst deactivation is the main reason for low petrochemical yield in catalytic fast pyrolysis (CFP) of biomass. ZSM-5 catalysts modified by chemical liquid deposition (CLD) and acid dealumination (AD) were prepared to improve petrochemical yields for CFP of pinewood. The results showed that CLD by SiO 2 led to the coverage of strong acid sites, while AD favored the removal of superficial acid sites. CFP of pinewood showed that the relative area ratio of BTX was boosted by 37.2% and 30.4% over modified ZSM-5 catalysts by CLD and AD, respectively. The yield of indenes and naphthalenes which were important precursors of heavy coke decreased sharply. Considering environmental cost and catalytic performance, CLD seems to be a preferable modification method over ZSM-5 in the catalytic pyrolysis of biomass for petrochemicals.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2017
·
IF 4.164
Beibei Hu,Yue Yuan,Yun Yan,Xiaoping Zhou,Yue Li,Qiming Kan,Sanming Li
A novel bolaamphiphile surfactant N , N ′-(dodecane-1, 12-diyl) bis (2,6-diaminohexanamide) (DADL) was designed and synthesized using l -lysine and 1,12-diaminododecane as the hydrophilic and hydrophobic part, respectively. After separation and purification, the structure of the synthetic bolaamphiphile surfactant was verified by FTIR, MS and 1 H NMR. The synthetic bolaamphiphile was able to self-assemble to form vesicles. After formulation screening, vesicles loaded with 5-Fluorouracil (5-Fu) were prepared with Tween 60 and DADL by sonication and were examined by dynamic light scattering and transmission electron microscopy. Micro-FTIR was applied to investigate the conformation of the bola molecules within the vesicle membrane. The release profile of the vesicles showed a pH-sensitive and sustained release. No significant toxicity was observed in an in vitro cell viability assay. The antitumor efficacy of the 5-Fu-loaded vesicles on H 22 tumor-bearing mice was remarkably high due to the EPR effects. These results show that our novel bolaamphiphile derived from lysine has excellent potential as a pH-sensitive drug carrier.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2015
·
IF 3.088
Longfei Li,Lin Chen,Huan Zhang,Yongzhen Yang,Xuguang Liu,Yongkang Chen
Temperature and magnetism bi-responsive molecularly imprinted polymers (TMMIPs) based on Fe 3 O 4 -encapsulating carbon nanospheres were prepared by free radical polymerization , and applied to selective adsorption and controlled release of 5-fluorouracil (5-FU) from an aqueous solution. Characterization results show that the as-synthesized TMMIPs have an average diameter of about 150 nm with a typical core–shell structure, and the thickness of the coating layer is approximately 50 nm. TMMIPs also displayed obvious magnetic properties and thermo-sensitivity. The adsorption results show that the prepared TMMIPs exhibit good adsorption capacity (up to 96.53 mg/g at 25 °C) and recognition towards 5-FU. The studies on 5-FU loading and release in vitro suggest that the release rate increases with increasing temperature. Meanwhile, adsorption mechanisms were explored by using a computational analysis to simulate the imprinted site towards 5-FU. The interaction energy between the imprinted site and 5-FU is − 112.24 kJ/mol, originating from a hydrogen bond , Van der Waals forces and a hydrophobic interaction between functional groups located on 5-FU and a NIPAM monomer. The electrostatic potential charges and population analysis results suggest that the imprinted site of 5-FU can be introduced on the surface of TMMIPs, confirming their selective adsorption behavior for 5-FU.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Xu Zhao,Fuxin Yang,Wentao Li,Houzhang Tan,Lijuan Gao,Yanhao Jiao
With the urbanization and population growth, the disposal of plastic waste has become a significant challenge, as the traditional methods often result in pollution and resource wastage. Pyrolysis technology offers a sustainable solution by converting the waste plastics into valuable gas or liquid fuels. The co-pyrolysis of plastics and biomass is an effective approach for synergistically managing these two types of solid waste. The polyethylene (PE) and salix psammophila (SP) was used to investigate the gas production characteristics and polycyclic aromatic hydrocarbons (PAHs) formation during the co-pyrolysis. Additionally, Cu/ZSM-5, Co/ZSM-5, and Ni/ZSM-5 catalysts were employed to investigate the effects of different metal-loaded catalysts on the co-pyrolysis process. The results indicate that, with the increase of the pyrolysis temperature, the yield of gas-phase products gradually increases, solid residue decreases, and liquid-phase products initially increase before declining, reaching their maximum at 500 °C. The synergistic effect promotes the formation of C 2 H m (C 2 H 2 , C 2 H 4 , C 2 H 6 ) and CH 4 , leading to the increase of the gas-phase product yields compared to the individual pyrolysis. The addition of catalysts further enhances the gas production: Cu/ZSM-5 boosts H 2 yield, Co/ZSM-5 shows selectivity for CH 4 and C 2 H m , and Ni/ZSM-5 exhibits better selectivity for CO and H 2 . Under the various pyrolysis conditions, aromatic compounds and aliphatic hydrocarbons consistently dominate the liquid-phase products. With the increase of the pyrolysis temperature, the proportion of aliphatic hydrocarbons decreases, while the proportion of aromatic compounds increases. The addition of catalysts reduces the proportions of both aliphatic and aromatic compounds. PAHs generation is temperature-dependent, significantly increasing at 700 °C. At the low pyrolysis temperatures, the co-pyrolysis reduces PAHs yield, but at high temperatures, PAHs formation increases. The addition of catalysts decreases PAHs yield and toxicity equivalency. Cu/ZSM-5 promotes the cracking of two-ring PAHs, reducing two-ring PAHs yield. Co and Ni catalysts enhance the selective aromatization of small hydrocarbon molecules, forming low-ring PAHs and limiting PAHs aggregation. Overall, Ni/ZSM-5 demonstrates the best performance in enhancing gas production and reducing PAHs emissions, followed by Co/ZSM-5 and Cu/ZSM-5.
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2025
·
IF 7.8
Zhentao Wang,Jian Zhang,Shanshan Guo,Yufei Cai,Ling Ma,Yuting Huang,Shucheng Wu,Weibing Wu,Weirong Zhao
Biomass catalytic pyrolysis for the production of aromatics as an alternative to petrochemical resources is a promising technology in the context of carbon neutrality. The aromatization of furans presents a novel pathway for converting biomass into aromatics. In this study, four binary molten chlorides (NaCl-FeCl 2 , NaCl-MnCl 2 , NaCl-ZnCl 2 , and NaCl-MgCl 2 ) were selected for the pyrolysis of pine sawdust. The thermal stability and eutectic points of the binary molten chlorides were tested by TG-DSC. The introduction of binary molten chlorides significantly increased the selectivity for furans in bio-oil, reaching 72.2–91.8 area% for NaCl-ZnCl 2 and 42.8–71.2 area% for NaCl-FeCl 2 . Commercial HZSM-5 was characterized by SEM, XRD, BET, NH 3 -TPD, and Py-IR, and HZSM-5/cordierite monolithic catalysts were prepared. Co-pyrolysis of pine sawdust and polypropylene in binary molten chlorides were conducted, combined with in-situ or ex-situ catalytic processes. Furans generated from the pyrolysis of pine sawdust in binary molten chlorides served as key intermediates for the production of aromatics with high selectivity in a single step. In ex-situ catalytic pyrolysis, the highest selectivity for aromatics reached 91.2 area%. The van Krevelen diagram indicated that the aromatics from bio-oil had the potential to substitute ethylene tar in carbon black production. Diels–Alder reactions were discussed in the proposed reaction pathways for catalytic co-pyrolysis.
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Leilei Zhou,Liyan Zhang,Jingrong Li,Tingting Xiao,Peikai Luo,Xinluona Su,Haiyang Cheng,Fengyu Zhao
The hydrodeoxygenation of fatty acids and esters is a critical pathway to produce biofuels. We report an efficient RuRe/ZSM-5(18) catalyst for hydrodeoxygenation of methyl laurate, the selectivity of n -C 12 H 26 reached up to 95.2 % at complete conversion under the reaction conditions of 200 °C, 3 MPa H 2 , 3 h. The contribution of ReO x and acid sites was discussed from the perspective of dynamics and thermodynamics. ReO x was available for the adsorption of substrate and intermediates, the acidity from ReO x species and ZSM-5 are conducive to the cleavage of C O bond. The synergistic effects of ReO x and Brønsted acid sites induced Ru 0 species to be electron-deficient, which preferred to adsorb aldehyde group in a linear adsorption configuration and facilitated for the hydrogenation of the aldehyde intermediate to alcohol, followed by dehydration to produce hydrocarbons. Thus, RuRe/ZSM-5(18) catalyst presented superior activity and chemoselectivity in the hydrodeoxygenation of methyl laurate as well as a series of fatty acids and esters without loss in carbon numbers in reactant.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Fuzheng Fu,Furui Hu,Zi Yu,Yongxin Liang,Tao Gan,Huayu Hu,Zuqiang Huang,Yanjuan Zhang
The existing photocatalytic systems are difficult to achieve high selectivity and conversion for the oxidation of 5-hydroxymethylfurfural (HMF) under mild conditions. MnO 2 exhibits notable tunability in valence state, but its photocatalytic oxidation efficiency is limited by the poor absorption in near-infrared region, insufficient oxygen adsorption, and slow charge transfer. To overcome these limitations, an innovative MnO 2 @Bi 2 MoO 6 /kaolinite (MnO 2 @BMO/KL) composite photocatalyst was synthesized by the hydrothermal and co-precipitation techniques, and the as-prepared photocatalyst was used for selective photocatalytic oxidation of HMF to produce 2,5-diformylfuran (DFF). The combination of MnO 2 , three-dimensional layered Bi 2 MoO 6 (BMO), and kaolinite enhanced electron transport and oxygen adsorption. The incorporation of kaolinite as a support material led to the structural transformation of BMO, while the in-situ grown amorphous MnO 2 trapped and accelerated electron transfer to adsorbed O 2 , thus efficiently segregating the photo-generated charges to enhance the utilization rate. MnO 2 @BMO/KL achieved almost complete conversion of HMF (>99.0 %) and a DFF yield of 83.0 % after 6 h of visible light irradiation. Additionally, MnO 2 @BMO/KL exhibited excellent structural stability over 6 cycles. The synergistic action of singlet oxygen ( 1 O 2 ) and superoxide ( • O 2 − ) was crucial in promoting the selective oxidation of HMF, while minimal generation of hydroxyl radical (•OH) reduced the risk of overoxidation. This study provides new insights into the development of economical and stable non-precious metal photocatalysts for highly selective conversion of biomass-derived chemicals.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）