CRYSTENGCOMM
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2021
·Vol. 23
·期 15
·2793-2800
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IF 3.545
Xueshuai Chen,Rongli Jiang,Yu Gao,Zihan Zhou,Xingwen Wang
In this work, nano-ZSM-5 zeolite with superior catalytic properties was synthesized from LAPONITE® as one of the Si sources by a dry gel conversion (DGC) method, and its crystallization mechanism was investigated as well. The properties of ZSM-5(Z-L) synthesized from LAPONITE® as one of the Si sources and ZSM-5(Z-T) synthesized from tetraethylorthosilicate (TEOS) as a single Si source have been compared. The results show that LAPONITE® is an important factor for the formation of nanocrystals with high crystallinity. It can not only act as the Mg and Si source for the zeolite synthesis but also exert a “confined space” effect to control ZSM-5 crystal growth. The Z-L sample with nanosized crystals can shorten the reactant and product diffusion path length, which seriously improves diffusion efficiency and results in longer catalytic stability. This work provides a novel and efficient route for synthesis of nano-ZSM-5 zeolite.
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LWT-FOOD SCIENCE AND TECHNOLOGY
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2021
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IF 4.952
Zheng Zhou,Yu-Ying Zhang,Jing-Xuan Gao,Li-Xin Ma,Xu-Hui Huang,Jie Zheng,Xiu-Ping Dong,Lei Qin
This study investigated the changes in free amino acids (FAAs), 5′-nucleotides, and lipid compositions of Manila clams ( Ruditapes philippinarum ) collected from December 2017 to November 2018. High-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry was used to quantify twenty-one FAAs and six 5ʹ-nucleotides. Lipid profiles were explored by ultra-performance liquid chromatography coupled with a Q-Exactive Orbitrap mass spectrometer with an untargeted lipidomic approach. Results showed significant monthly changes of FAAs, 5′-nucleotides, and lipids profiles. Alanine , glutamic acid , glycine, and aspartic acid , which contributed to the sweet and umami flavor, were the most abundant FAAs in Manila clams. Totally 90 glycerides, 76 glycerophospholipids , 21 lyso-glycerophospholipids, and 52 fatty acids were identified in Manila clams. Among these lipids, most of them possessed a high-level of unsaturation degree. The unsaturation degree of lipids in February, March, and April was the highest, showing the best nutritional value of Manila clams.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2021
·
IF 3.764
Hailin Zhao,Bingjing Tang,Jie Tang,Yafeng Cai,Yao Cui,Hao Liu,Li Wang,Yunsong Wang,Wangcheng Zhan,Yanglong Guo,Yun Guo
Catalytic oxidation is believed to be the most efficient method for indoor formaldehyde purification. Herein, we reported that the Pt/Na-ZSM-5 catalyst with low Pt loading (0.16 wt %) prepared by depositing Pt on Na+ ion-exchanged ZSM-5 could completely oxidize 300 ppm formaldehyde in 2.5 vol % H2O at 32 °C and maintain its activity during the 62 h-long stability test. Multiple characterizations revealed that the presence of Na species significantly enhanced formaldehyde adsorption ability and made Pt species tend to exist in the form of metal Pt through electron transfer from Na to Pt, which promoted the activation of oxygen and opened a new efficient formaldehyde oxidation pathway, namely, direct decomposition of formate. The synergistic effects resulted in the TOF of Pt(0.16)/Na-ZSM-5 being about nine times higher than that of Pt(0.50)/ZSM-5. Our study showed that utilizing an alkali metal to tune the surface acidity/basicity of the support and the state of the supported noble metal was a promising way to improve the intrinsic catalytic performance and reduce noble metal usage.
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Journal of Energy Chemistry
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2021
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IF 9.676
Zhiguo Zhu,Xiongjie Gao,Xiuming Wang,Mengdie Yin,Qingyao Wang,Wanzhong Ren,Bo Wang,Hongying Lü,Weiping Liao
The selective aerobic oxidation of biomass-derived 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid (FDCA, a potential renewable substitution of fossil-based terephthalic acid to produce polyethylene 2,5-furandicarboxylate plastic) is an appealing transformation for constructing eco-friendly and sustainable chemical processes. Au supported catalysts have showed encouraging performances for this well-received conversion, whose catalytic behavior was greatly affected by the adopted support derived from the existence of metal-support interactions. Herein, a series of Mg-Beta zeolites were hydrothermally synthesized via developed structural reconstruction, which were employed as basic supports for Au catalysts to construct bifunctional catalysts. The relationship between structure (Au particle size, basicity within zeolites and Au δ+ contents) and FDCA yield was concretely established. The conclusion was made that the utilization of Mg-Beta zeolites with strong basicity as the support could not only improve the FDCA yield but also decrease the amount of additional base. Furthermore, the possible reaction mechanism was also proposed via tracking time-dependent variations of corresponding organics and controlled experiment. This work provides some guidance for rationally designing multifunctional catalysts in the view of integrating metal catalysts with metallosilicate zeolites, which was beneficial to the catalytic upgrading of organic compounds with multiple functional groups.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
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IF 2.694
Yang Cong,Cunbin Du,Meng Wang,Zhouyu Jiang,Mingliang Wang
In this work, the phase equilibrium solubility of 5-fluorocytosine (5-FC) in dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), 1-butanol, acetonitrile, 1-propanol, 1,4-dioxane, acetone, ethyl acetate, 2-propanol, 2-butanone, and mixture systems (DMSO + 2-propanol and DMF + 2-propanol) at a series of temperatures (283.15–323.15 K) is determined, and model correlation, solvent effect, and preferential solvation analysis are researched. The solubility of 5-FC is related to temperature, which decreases with decreasing temperature. For monosolvent systems, the mole solubility order is DMSO > DMF > 1-butanol > 1-propanol > 2-propanol > acetone > 2-butanone > 1,4-dioxane > acetonitrile > ethyl acetate. The solvent effect has been studied in monosolvents, hydrogen-bonding acceptor (HBA) interactions and nonspecific dipolarity/polarizability interactions favor dissolution, and solvent self-cohesiveness is not beneficial to dissolution. For two mixture systems, the mole solubility of 5-FC in DMSO + 2-propanol solvent systems is higher than that in DMF + 2-propanol solvent systems. A dimensionless parameter (δ) is defined to observe the deviation from ideality of mixed solvents whose values are all greater than zero. The equilibrium constant of the solvent exchange process (Kps) can be used to evaluate the preferential solvation of 5-FC. DMSO or DMF dissolves 5-FC in the local region around 5-FC preferentially. The equilibrium solubility data is correlated by four correlation models (modified Apelblat, λh, CNIBS/R-K, and Jouyban–Acree models). The greatest relative average deviation (RAD) and root-mean-square deviation (RMSD) values are 2.01% and 11.87 × 10–5 in pure solvent systems and 2.20% and 5.99 × 10–5 in mixture systems, respectively. These four models show excellent correlation with the experimental solubility data.
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APPLIED CATALYSIS A-GENERAL
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2021
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IF 5.706
Xiaochao Xian,Mengjun He,Yakai Gao,Yi Bi,Yirong Chu,Jun Chen,Lichun Dong,Jin Wang,Shuo Zhao
Reducing the acid density and strength of HZSM-5 zeolite are typical strategies to inhibit coke deposition during catalytic cracking reactions. Herein, direct titration of HZSM-5/H 2 O suspension using dilute NaOH aqueous solution at room temperature was introduced to neutralize excessive Brønsted acid sites of HZSM-5 zeolite (Si/Al = 25). SEM, XRD, N 2 adsorption and n -propylamine temperature-programmed decomposition confirmed that simultaneous acid strength weakening and acid density reducing were achieved without obvious influence on crystalline or textural property. The evolution of the surface charge during the titration process tracked by Zeta-potential measurement reveals that the mechanism of such neutralization is: liquid phase neutralization between H + and OH − & solid phase ion exchange between Na + and H + . Supercritical catalytic cracking of n -dodecane over a series of partial neutralized HZSM-5 catalysts showed that moderate neutralization can enhance the conversion of n -dodecane by alleviating both the coke amount and harmfulness per unit mass of coke.
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CHEMOSPHERE
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2021
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IF 7.086
Wanyi Huang,Yixing Yuan,Dan Zhong,Wencheng Ma,Yuan Yuan,Peng Zhang
In this study, we investigated the use of pipe growth rings from water distribution networks as a catalyst in heterogeneous Fenton-like oxidation processes. The major constituents of real pipe growth rings (α- and γ-FeOOH) were prepared and considered as a simulated growth ring (SGR). Its performance in removing 5-bromosalicylic acid (5-BSA), a novel phenolic halogenated disinfection byproduct , was examined. SGR exhibited strong catalytic ability and a certain degree of adsorption capacity. Under acidic conditions, the adsorption and oxidation efficiencies were 32.65% and 87.67%, respectively. Furthermore, 72.19% of 5-BSA could be oxidized even at pH 0 of 7. Kinetic characterizations at various temperatures revealed that both the adsorption and catalytic oxidation processes followed pseudo-second-order kinetic models and were surface-controlled with high activation energies (31.26 and 23.58 kJ mol −1 , respectively). Ecotoxicity analyses of the transformation products (TPs) showed that the SGR/H 2 O 2 system could effectively reduce the toxicity of 5-BSA. Moreover, the number of iron ions leaching from SGR was below 0.1 mg L −1 in all experiments. The results of this study support further investigation of using real pipe growth rings in off-line water treatment , as well water network contamination remediation.
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PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2021
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IF 4.539
Jingyi Liu,Shuhua Han,Yongfeng Hu,Chih-Wen Pao
A highly sensitive and low-cost optical nanosensor of organic-inorganic hybrid material for pesticide ferbam detection was prepared by utilizing a novel organic siloxane precursor obtained from riboflavin-5′-phosphate sodium salt (Rf). A panel of characterizations was carried out to understand the structure, morphology and surface chemistry of the Rf periodic mesoporous organosilica (Rf-PMO) spherical nanosensors. For the Rf-PMO materials, the doped silica nanoparticles exhibit strong fluorescence emission at 520 nm, on account that the greater steric hindrances and the more separated state of π-conjugate planer platforms between Rf molecules embedded within the silica framework can both enhance the fluorescence emission and reduce the self-quenching of fluorescence produced by stacking aggregation of Rf. The electron spin resonance (ESR) spectra prove that the prepared Rf-PMO materials can participate in the redox reaction through electron transfer with the pesticide ferbam. Utilized the reducing reaction mechanism of Rf-PMO, it is applied to detect pesticide ferbam with high sensitivity and selectivity, with the limit of detection (LOD) in aqueous solution as low as 6.97 × 10 −9 M. Moreover, the X-ray absorption near-edge spectroscopy (XANES) of Fe K -edge shows a coordination structure through the interaction between iron ions from ferbam and O and N atoms in Rf-PMO. X-ray photoelectron spectroscopy (XPS) further reveals the redox mechanism. Therefore, the designed and prepared Rf-PMO is potentially valuable to food safety monitoring involving ferbam as the nanosensor, due to its hypersensitivity and selectivity.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2020
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IF 2.627
Huan Li,Yao Zhong,Luxi Wang,Qiang Deng,Jun Wang,Zheling Zeng,Xinxiang Cao,Shuguang Deng
In the dehydration of fructose to 5-hydroxymethyl furfural (HMF), in situ produced water weakens the acid strength of the catalyst and causes the rehydration of HMF, causing unsatisfactory catalytic activity and selectivity. In this work, a class of benzenesulfonic acid-grafted metal–organic frameworks with strong acidity and hydrophobicity is obtained by the direct sulfonation method using 4-chlorobenzenesulfonic acid as sulfonating agent. The resultant MOFs have a specific surface area of greater than 250 m 2 ·g −1 , acid density above 1.0 mmol·g −1 , and water contact angle up to 129°. The hydrophobic MOF-PhSO 3 H exhibits both higher catalytic activity and selectivity than MOF-SO 3 H in the HMF synthesis due to its better hydrophobicity and olephilicity. Moreover, the catalyst has a high recycled stability. At last, fructose is completely converted, and 98.0% yield of HMF is obtained under 120 °C in a DMSO solvent system. The successful preparation of the hydrophobic acidic MOF provides a novel hydrophobic catalyst for the synthesis of HMF.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
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IF 3.573
Qi Lu,Yuanzhe Gong,Jianwen Lu,Jian Liu,Yulong Wu
Stearic acid (SA) and hexadecanamide (HA), which are model compounds of algae-based bio-oil, were used to produce aromatics for catalysis by a hierarchical HZSM-5 zeolite under hydrothermal conditions. The results showed that the hierarchical HZSM-5 zeolite was more active than the traditional HZSM-5 parent zeolite. The molar yield of toluene, ethylbenzene, and xylene could reach (1.14 ± 0.05) × 100% (normal weight percentage yield = 40.77 wt %) when the reaction temperature was 400 °C. Moreover, the catalyst was stable and recyclable under hydrothermal conditions. Besides, the addition of acetic acid remarkably improved the deoxygenation (or denitrification) and aromatization efficiencies of the SA and HA mixture by more than 25%. This study provides a feasible approach to the valorization of algal biomass and the production of aromatics.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2020
·
IF 4.551
Chunhui Cheng,Guixian Li,Dong Ji,Yu Zhao,Jianyi Shen
HZSM-5 is a widely used catalyst for the conversion of methanol to aromatics (MTA), but its single micropore system often results in severe diffusion limitations, leading to the decrease of reaction rate and the change of selectivity to aromatics, as well as affecting the carbon deposition and catalyst deactivation . Thus, an ingenious protective desiliconization method with a mixed solution of sodium hydroxide and tetrapropylammonium hydroxide as a desiliconization agent was developed to create hierarchical porous systems without destruction of the main structure of the molecular sieve . Such modification leads to the greatly increased mesoporous volume from 0.12 to 0.38 cm 3 g −1 , and only slightly decreased microporous volume from 0.12 to 0.09 cm 3 g −1 . However, the desiliconization sharply increases the acidity of the catalyst (from 0.248 to 0.341 mmol g −1 for the strong acid sites), which may significantly affect the distribution of aromatics and accelerate the carbon deposition rate . Thus, the deposition of inert SiO 2 on the catalyst surface is subsequently carried out to passivate the surface acidity and adjust the orifice of the catalyst. Accordingly, a hierarchical porous HZSM-5 molecular sieve catalyst (Si@Z5-Na + TP) with suitable acidity is precisely prepared, which exhibits the high selectivity to benzene, toluene and xylenes (BTX) with the excellent anticoking ability in the MTA reaction. The selectivity to BTX in aromatics (63.32%) and the carbon deposition rate (0.91 mg g cat −1 h −1 ) over the Si@Z5-Na + TP catalyst are both much more superior than those over the parent HZSM-5 catalyst (47.5% and 2.23 mg g cat −1 h −1 , respectively).
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Molecular Catalysis
·
2021
·
IF 5.062
Kang Hu,Man Zhang,Biying Liu,Zhiyu Yang,Ruiqi Li,Kai Yan
2,5-furandicarboxylic acid (FDCA) is a key precursor for the sustainable synthesis of environmentally friendly materials such as polyethylene 2,5-furandicarboxylate (PEF). Developing noble-metal free and robust electrocatalysts are of great importance for the eco-friendly upgrading of biomass-derived 5-hydroxymethylfurfural (HMF) to produce FDCA. Herein we demonstrated a facile one-step hydrothermal method to grow tungsten trioxide (WO 3 ) nanorods on Ni foam, which was efficient for the electrochemical oxidation of HMF to FDCA. The 3D porous WO 3 /Ni electrode was controllably synthesized at low temperature with the aid of polyethylene glycol (PEG) template. Three types of electrodes were investigated and the catalytic results showed excellent electrochemical performance with the high electrochemically active surface area (ECSA) up to 40.0 cm 2 , 99.4 % HMF conversion rate, 88.3 % FDCA yield and 88.0 % Faradaic efficiency in 1.0 M KOH electrolyte under ambient conditions, avoiding the traditionally harsh environment (e.g. extra oxygen sources, high temperature and pressure). Besides, the product distribution, reaction kinetics and mechanisms were also investigated. This work provides an alternative and efficient way of electrocatalytic processing of biomass-derived monomers using noble-metal free catalysts under ambient conditions.
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