Nanoscale
·
2020
·Vol. 12
·期 34
·17902-17914
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IF 6.895
Lifang Chen,Ting Zhang,Hongye Cheng,Ryan M. Richards,Zhiwen Qi
In order to develop highly active non-precious metal catalysts for the selective oxidation of the platform compound 5-hydroxymethylfurfural (HMF) to the value-added bio-chemical 2,5-diformylfuran (DFF), we prepared high purity bivalent Mn5O8 nanoplates by a microwave-assisted ionic liquid route. The precursor of bivalent Mn5O8 nanoplates was formed through π–π stacking between imidazolium rings of the ionic liquid 1-butyl-3-methyl-imidazolium chloride and extending hydrogen bonds between Cl anions and hydrohausmannite. An oriented aggregation growth occurred on the basis of the Ostwald ripening under microwave heating. The high purity bivalent Mn5O8 nanoplates obtained through calcination at 550 °C for 2 h exhibited high HMF conversion (51%) and DFF selectivity (94%) at 5 bar of oxygen pressure in 2 h. The high concentration of Mn4+ on the exterior surfaces of Mn5O8 nanoplates as active sites coupled with good crystallinity played key roles for desirable mass and heat transfer, and for fast desorption avoiding over-oxidation. The reaction process over the Mn5O8 nanoplates was proposed based on the understanding of Mn4+ active centers and lattice oxygen via a Mn4+/Mn2+ two-electron cycle to enhance their catalytic performance. Furthermore, the Mn5O8 nanoplates could be readily recovered and reused without loss of catalytic activity. Thus, the high purity Mn5O8 nanoplates with good catalytic performance raises the prospect of using the type of sole metal oxide for practical applications.
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高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Zi Zeng,Jiaoyang Xie,Yue Guo,Ruiheng Rao,Bo Chen,Lihua Cheng,Ying Xie,Xinping Ouyang
Highly dispersed Fe Pd bimetallic catalyst supported on HZSM-5 (Fe-Pd/HZSM-5) was prepared by impregnation method for the hydrogenolysis of lignin. The correlation between the textural properties of the catalyst and its catalytic activity to lignin hydrogenolysis were investigated. The presence of Fe facilitates the dispersion of Pd, and the particle size decreases from 6.1 nm for 3.0 wt% Pd/HZSM-5 (Pd-3.0) to 2.5 nm for 9.0 wt% Fe-1.0 wt% Pd/HZSM-5 (FP-1.0). Fe is mainly existed in the oxidized state which means that electrons in Pd tend to transfer to FeO x , facilitating the activation of H 2 to form active H atoms. Due to the geometric and electronic synergistic effects , FP-1.0 bimetallic catalyst exhibits a good catalytic activity to lignin hydrogenolysis, contributing to as higher as 98.17% of lignin conversion and 27.92% of aromatic monomers yield under the optimal reaction conditions of 1 MPa H 2 at 320 o C for 120 min in ethanol-water solvent. FP-1.0 bimetallic catalyst with low cost and highly catalytic activity may be a potentially useful catalyst for selective hydrogenolysis of lignin.
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MICROPOROUS AND MESOPOROUS MATERIALS
·
2020
·
IF 4.551
Tingting Qi,Jing Shi,Xishuo Wang,Kun Dong,Yong Luo,Jiawei Teng,Guang-Wen Chu,Hai-Kui Zou,Baochang Sun
Hierarchical (micro/mesopore) ZSM-5 zeolites were hydrothermally synthesized in a rotating packed bed (RPB) which substantially enhances micromixing for the high viscosity reaction system. Herein, the effects of four operating processes with different micromixing intensity on nucleation/crystal growth process as well as physicochemical properties of ZSM-5 zeolites were investigated. Results indicate that enhancing micromixing by RPB in the zeolite synthesis could facilitate the formation of Al sites and shorten the nucleation and crystallization period. ZSM-5 samples prepared by RPB exhibit hierarchical structure, smaller average particle size, more uniform particle size distributions , larger specific surface areas, higher catalytic stability as well as more acid sites than those obtained by (stirring tank reactor) STR. While adopting the ZSM-5 samples prepared by RPB for catalyzing C4-olefin cracking reaction, the conversion of C4-olefin and yield of propylene are higher than those obtained by STR.
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高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 151
·期 8
·2436-2444
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IF 3.186
Hu Yaoping,Li Mingfu,Gao Zhijin,Wang Lei,Zhang Jian
Abstract Waste Polyethylene terephthalate plastic bottles were used as precursors to fabricate carbon dots (CDs) via air oxidation and sulfuric acid hydrothermal treatment. Owing to the nano-size effect and abundant acidic groups, CDs allowed their application as a novel solid acid for quasi-homogeneous catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF). Under the optimal condition, an ultra-high yield of HMF was 97.4% along with 100% fructose conversion at low temperature of 50 °C when [BMIM]Cl/ethanol was used as solvent. The CDs catalyst also displayed a prominent recyclability and was used for six recycles without massive loss in catalytic activity. Furthermore, 98.6% of HMF could be obtained from final products. The findings provide a novel sustainable route using recyclable plastics to synthesize carbon dots with a superior catalytic performance for conversion of biomass to important bio-based platform chemicals. Graphic Abstract
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Expert Opinion on Drug Delivery
·
2020
·
IF 4.838
Pu Guo,Chao Pi,Shijie Zhao,Shaozhi Fu,Hongru Yang,Xiaoli Zheng,Xiaomei Zhang,Ling Zhao,Yumeng Wei
Background A novel nanoemulsion (CU/FU-LN) was developed as an oral 5-fluorouracil and curcumin co-delivery system for synergistic efficacy against liver cancer.Methods MTT assay, confocal laser scanning microscope, and H&E staining were utilized to establish the efficacy and safety of CU/FU-LN.Results The AUC(0-t) of CU/FU-LN was 8.85-fold and 8.59-fold greater than those of CU and FU, respectively. The IC50 of CU/FU-LN was 4.6-fold and 4.9-fold lower than those of FU and CU in HepG2 cells, respectively. In vivo anti-tumor trials, the tumor inhibition rate was significantly elevated by CU/FU-LN (49.29%), compared 24.84% and 4.72% for FU and CU, respectively. Ki-67 immunohistochemical analysis revealed that CU/FU-LN had an obvious anti-proliferation effect. The IC50 of CU/FU-LN in L02 cells was 1.51-fold and 2.60-fold higher than those of CU and FU, respectively. Certain vital organs in the mice of the CU/FU-LN group showed markedly fewer lesions than those of the CU, FU, and CU+FU groups. The CU/FU-LN treatment caused no significant change in mouse body weight relative to the control group (P > 0.05). Conclusions We successfully prepared a promising co-delivery platform for the synergistic treatment of liver cancer and it has a comparatively enhanced efficacy and mitigated toxicity.
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BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2020
·
IF 2.985
Yafei Wang,Huimin Liu,Jianmin Wu,Yunjian Liao,Daifeng Lu,Feng Dong,Hongxi Li,Zhitao Zhang,Yongyun Lian
Periprosthetic osteolysis (PIO) caused by wear particles is the main cause of implant failure, which is regulated by nuclear factor κ B receptor activator ligand (RANKL)/osteoprotegerin (OPG) system. At present, there is a lack of effective drugs to prevent or treat PIO. Previous studies have confirmed that DNA methylation is closely related to postmenopausal osteoporosis and can affect the expression of OPG and RANKL . However, the relationship between DNA methylation and PIO is not clear. In this study, we investigated the inhibitory effect of 5-Aza-2-deoxycytidine (AzadC) on osteolysis induced by titanium particles in a mouse model. This inhibition mechanism is achieved by changing the ratio of RANKL/OPG in the osteolysis model. In conclusion, there is a relationship between DNA methylation and PIO. AzadC has a certain inhibitory effect on osteolysis induced by titanium particles. Regulating DNA methylation may be a new way to treat PIO. Our findings lay a foundation for epigenetic understanding and intervention of osteolysis.
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高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 34
·期 11
·e5932
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IF 3.14
Yanming Jia,Junwen Wang,Kan Zhang,Chuanmin Ding
A highly shape-selective and relatively long-lifetime HZSM-5-based catalyst (Zn-2P/HZSM-5) was prepared by chemical modification with both ZnSiF 6 ·6H 2 O and H 3 PO 4 solution. The phosphoric acid modification could effectively modulate the Brønsted acid strength of the HZSM-5 catalyst, which promotes the oligomerization, alkylation, cyclization, and hydrogen transfer reactions. The introduction of Zn-Lewis acid sites significantly improved the dehydroaromatization of higher olefins. All of these were very beneficial for the generation of BTX (i.e. b enzene, t oluene, and x ylene) hydrocarbons in aromatization of methanol. The coke amount and the average rate of coke formation decreased over the Zn-2P/HZSM-5 catalysts, which may largely be ascribed to its lower strong acid sites and lower outer surface acidity. The catalytic performance of methanol aromatization showed that the Zn-2P/HZSM-5 catalyst exhibited the highest BTX selectivity of about 46.76% and the longest catalytic lifetime of about 498 h at T = 400 °C, P = 0.1 MPa, and weight hourly space velocity = 0.7 h −1 .
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Ji Guo,Zhongli Ji
The filtration efficiency of coalescent filter elements used in gasoline and diesel oil dehydration in refineries is unsatisfactory and not sufficient to meet downstream water-content requirements. Thus, it was necessary to improve the internal filter medium of traditional oil-water coalescent filter elements. Zeolite membrane is a kind of material with superhydrophilicity and strong adsorption for and permeability to water. In this study, ZSM-5 zeolite membrane with superhydrophilic properties was successfully prepared by an in situ hydrothermal synthesis. Two experiments with zeolite membranes were performed, including membrane filtration and membrane coalescence tests. Membrane filtration tests showed that it possessed strong adsorption for and permeability to water and that the oil-water filtration efficiency for 32 # turbine oil, kerosene, and corn oil were all >95 %. In the second part of this study, composite filtration was carried out using the membrane as well as hydrophilic glass fiber and hydrophobic polypropylene (PP) membranes. Membrane coalescence test demonstrated that, when the oil contained a phenol/water combination, the water rejection rate of the composite filtration with ABACBA (A, PP fiber; B, glass fiber; and C, molecular sieve membrane) was 90.8 %, with the downstream water content controlled within 100 mg/L and the quality factor increased from 0.18 to 0.23, relative to other systems. These experimental results showed potential for improving the current oil-water coalescent filters.
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高影响因子
Catalysts
·
2020
·Vol. 10
·期 3
·311
·
IF 3.52
Jing Shao,Shuyuan Cheng,Zhaoxu Li,Bichun Huang
A ZSM-5 zeolite with a hierarchical pore structure was synthesized by the desilication-recrystallization method using tetraethyl ammonium hydroxide (TEAOH) and cetyltrimethylammonium bromide (CTAB) as the desilication and structure-directing agents, respectively. The MnOx/ZSM-5 catalyst was synthesized by the ethanol dispersion method and applied for the low-temperature selective catalytic reduction of NOxwith NH3. The results showed that NOxconversion of the hierarchical MnOx/ZSM-5 catalyst could reach 100% at about 120 °C and could be maintained in the temperature range of 120–240 °C with N2selectivity over 90%. Furthermore, the hierarchical MnOx/ZSM-5catalyst presented better SO2resistance performance than the traditional catalyst in the presence of 100 ppm SO2at 120 °C. XRD, SEM, TEM, XPS, BET, NH3-TPD, and TG were applied to characterize the structural properties of the MnOx/ZSM-5 catalysts. These results showed that the MnOx/ZSM-5 catalyst had micropores (0.78 nm) and mesopores (3.2 nm) leading to a larger specific surface area, which improved the mass transfer of reactants and products while reducing the formation of sulfates. The better catalytic performance over hierarchical MnOx/ZSM-5 catalyst could be attributed to the higher concentration of Mn4+and chemisorbed oxygen species and higher surface acidity. The improved SO2resistance was related to the catalyst’s hierarchical pore structure.Keywords:hierarchical pore structure;MnOx/ZSM-5;NH3-SCR;SO2resistance
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高影响因子
FUEL
·
2021
·
IF 6.609
Mingjie Liao,Xin Ning,Junwen Chen,Jiajun Zheng,Wenlin Li,Ruifeng Li
Zeolite is one kind of the solid acid catalysts for the oligomerization process but surfers from rapid deactivation. In this specific study, a series of mesoporous ZSM-5 catalysts have been synthesized and evaluated in the 1-hexene oligomerization. XRD, BET, SEM, TEM, 27 Al MAS NMR, 29 Si MAS NMR, NH 3 -TPD, Py-FTIR and TGA analysis were used to characterize the physicochemical properties of zeolites. The synthesized mesoporous zeolites were found to be more stable in the reaction and the initial activity increase significantly compared with the common ZSM-5 zeolite . Moreover, the catalytic activity of mesoporous ZSM-5 zeolite is found to be closely related to the number and the distribution of acid sites. The mesoporous ZSM-5 zeolites with the lower amount of acid sites, moderate strength of Brønsted acid sites inhibiting the cracking and coke products. High L/B ratio enhanced the dimers formation. The efficiency was further highlighted by a high space–time yield (STY) of 557 mg·g cat −1 h −1 in the average stage at 260 °C. Compared to conventional ZSM-5 catalyst, the synthesized catalyst displayed excellent resistance to coke deposit.
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Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 10
·8927-8938
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IF 4.987
Zheng Zhangbin,Wang Chen,Chen Yihang,Wang Shijie,Guo Qianhui,Chang Chun,Tao Hongge,Xu Guizhuan
The production of 5-ethoxymethylfurfural (EMF) from renewable and abundant biomass feedstock has attracted great attention due to its potential applications in the chemistry and energy industries. As one of the most abundant biomass, glucose has great significance for the production of EMF in large scale. In this study, an efficient one-pot conversion of glucose into EMF catalyzed by ultra-stable Y zeolite (USY) was developed. The effects of process parameters including reaction temperature, reaction time, reactant concentration, and catalyst dosage on EMF yields were systematically investigated, and the respond surface methodology was further used to investigate the interactions of different parameters. Under the optimum reaction conditions of reaction temperature 200 °C, reaction time 10 min, the substrate concentration 100 g·L −1 , and catalyst dosage 1.8 ωt%, a EMF yield of 39.5 mol% can be obtained. Moreover, the products distribution was analyzed by GC–MS and a plausible reaction pathway of glucose one-pot alcoholysis reaction catalyzed by USY was put forward accordingly. At the same time, XRD, FTIR, BET, NH 3 -TPD, and Py-IR were used to characterize the reusability of USY, and the results showed that the structure of the catalyst was kept stable after being reused. After five cycles, the EMF yield was 31.4 mol% suggesting that the catalyst maintained high catalytic activity. Graphical abstract
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FIBERS AND POLYMERS
·
2021
·Vol. 23
·期 1
·98-106
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IF 2.153
Wang Meirong,Shi Sheng,Dai Jinming,Guo Hong,Hou Wensheng,Wang Shuhua,Jia Husheng,Yan Zhifeng,Ge Chao
The preparation of value-added products is an effective way to reuse waste cotton fabrics (WCFs). Seven kinds of choline chloride (ChCl)-based deep eutectic solvents (DESs) were rapidly formed and characterized. Performances of these ChCl-based DESs were evaluated in terms of degradation of WCFs to 5-hydroxymethylfurfural (5-HMF) without any additional catalyst. The degradation was characterized by high-performance liquid chromatography (HPLC) and scanning electron microscopy (SEM) method. The results showed that the DESs formed by ChCl and p -toluene sulfonic acid ( p -TSA) had the best effect in converting WCFs. Moreover, the stability of 5-HMF in the as-obtained DESs was also investigated. The highest 5-HMF yield was 10.20 % at 100 °C, with a reaction time of 90 min, and the molar ratio of hydrogen bond acceptor (HBA) to hydrogen bond donor (HBD) was 1:1.3 in ChCl/ p -TSA DESs system without a catalyst. The investigated DESs system offers a good alternative compared to the available WCFs degradation methods, considering its cost-efficiency, environmental, and operability aspects. Therefore, the green and environmentally friendly synthesis of 5-HMF from cellulose materials (WCFs) could be an effective method to realize the high-value utilization of waste textiles, having an important theoretical significance and practical value.
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