Biomass Conversion and Biorefinery
·
2021
·Vol. 12
·期 8
·3503-3511
·
IF 4.987
Huang Xin,Xu Anbang,Bu Xinyuan,Huang Yong,Ran Jingyu
Levoglucosenone (LGO), derived from catalytic pyrolysis of cellulose, has shown its potential as a bio-renewable platform for the production of fine and commodity chemical. In this study, we report a biphasic system for conversion of LGO to 5-hydroxymethylfurfural (HMF) and levulinic acid (LA) with a substantial yield. The hydrolysis parameters, including single-biphasic phase, catalyst, temperature, and reaction time, were investigated on LGO conversion, respectively. The results showed that NaCl/H 2 O-MIBK biphasic system led to a profoundly increase of HMF selectivity by 37% compared to aqueous phase. An increase of acid site significantly enhanced LGO conversion and meanwhile promoted overreaction of HMF to LA and humins. Thus, HMF yield was observed firstly increased and then decreased with a maximum yield of 53.6% by using oxalic acid as a catalyst. The biphasic system effectively suppressed the humins formation and resulted in a maximum total HMF and LA yield of 86.7%.
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GREEN CHEMISTRY
·
2020
·Vol. 23
·期 1
·405-411
·
IF 9.48
Huiyong Wang,Jingjing Cui,Yuling Zhao,Zhiyong Li,Jianji Wang
Ionic liquids (ILs) have been widely studied as effective reaction media or catalysts for the conversion of renewable resources to 5-hydroxymethhylfurfural (5-HMF). However, the separation of 5-HMF from ILs remains a significant challenge. Thus, the aim of this work is to develop a useful guideline for the selection and design of greener solvents for efficient separation of 5-HMF from ILs by a simple solvent extraction approach. To this end, 9 kinds of low-toxic and medium boiling point organic solvents and 10 kinds of ILs typically used in biomass conversion have been evaluated for the separation of 5-HMF. The effects of the solvent hydrogen bond acceptor capacity, anion type and cationic structure of the ILs on the separation of 5-HMF from the ILs are systematically investigated and the molecular interactions among 5-HMF, ILs and the solvent contained in the mixtures have been revealed by FTIR and 1H NMR measurements. It has been found that besides a low mutual solubility with ionic liquids, an ideal solvent should have strong hydrogen bond acceptor properties. At the same time, the interactions between the anion and cation of the ILs and the hydrogen bonding interaction of the anion with 5-HMF are also very important for the separation of 5-HMF. A weak interaction of the anion with 5-HMF and a strong interaction between the anion and cation of the ILs all result in the high extraction efficiency. Under the optimized conditions, the extraction efficiency of 5-HMF from the ILs is up to 61.0%, which is a record-breaking value at the current time. This finding provides a useful guide for the selection of greener solvents for the separation of 5-HMF from ILs.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Caidi Jin,Ning Xiang,Xiao Zhu,Shuang E,Kuichuan Sheng,Ximing Zhang
5-hydroxymethylfurfural (HMF) can be widely converted into value-added chemicals and fuels production. Herein, we reported a sustainable and efficient approach for synthesizing HMF directly from cellulose. Facile formylation of cellulose with green and recyclable formic acid was developed for cellulose formate (CF) production. CF with special net-like structure and high degree of formyl substitution was prepared. The resultant CF exhibited excellent catalytic conversion and selectivity for HMF production comparable to monomeric glucose as reactant in dimethyl sulfoxide (DMSO)-H 2 O media. In our work, we presented molecular dynamics simulations to elaborate the preferential coordination of DMSO around formyl group, which promoted the solvation of formylated substrate in DMSO-H 2 O mixture, and the HMF yielded could be protected by DMSO without further degradation to levulinic acid or humins.
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高影响因子
FUEL
·
2020
·
IF 5.578
Bing Xu,Minghui Tan,Xuemei Wu,Hailun Geng,Faen Song,Qingxiang Ma,Chunhui Luan,Guohui Yang,Yisheng Tan
Dehydroaromatization of propane to high value-added aromatics, especially benzene, toluene and xylene (BTX), has attracted widespread attention. Many works have been done to improve the catalytic performance of gallium loaded HZSM-5 catalysts. However, there were few reports focused on reducing the cracked by-products, such as methane and ethylene, derived from propane cracking reaction on external Brønsted acidic sites of zeolite. Herein, chemical liquid deposition (CLD) method was adopted to passivate the external strong Brønsted acid of Ga/HZSM-5, aiming to increase the most value-added BTX production by suppressing the undesired propane cracking reaction. The content of deposited SiO 2 on the external surface of zeolite was tunable by varying the amount of liquid deposition reagent and duration time of CLD process. The results showed that an appropriate content of SiO 2 on external surface of catalyst was beneficial to disable the external strong Brønsted acid sites. Due to depressing the undesired propane cracking reaction, BTX selectivity of 55% with propane conversion of 49% was achieved on Ga/Z5-4Si catalyst, higher than those of Ga/HZSM-5. Otherwise, prolonging the duration time of CLD process narrowed the micropore mouth size of zeolite, which could enhance the shape selective effect of Ga/ZSM-5 to increase the proportion of para-xylene in total xylene products.
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RSC Advances
·
2020
·Vol. 10
·期 50
·29618-29626
·
IF 3.119
Yanming Jia,Qinghua Shi,Junwen Wang,Chuanmin Ding,Kan Zhang
Hierarchical nano-ZSM-5 zeolites (Z5-X) with different grain sizes were synthesized by varying amounts of 3-glycidoxypropyltrimethoxysilane (KH-560) in the hydrothermal synthesis strategy. Moreover, the conventional ZSM-5zeolite(Z5), which was prepared without KH-560, was used as the reference sample. The crystalline phases, morphologies, porous characteristics, Si/Al molar ratios and acidic properties of all fresh catalysts were characterized using the X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), N2 adsorption–desorption, inductively coupled plasma atomic emission spectroscopy (ICP) and temperature programmed desorption of ammonia (NH3-TPD) techniques. Results show that the grain size and strong acid amount of zeolite decreased with the increasing amount of KH-560. The micropore surface areas and the corresponding volume of Z5-X changed less compared with Z5. Consequently, the high shape-selectivity of zeolite was preserved well under the addition of KH-560. However, the mesopore surface areas and the corresponding volume increased significantly with the increasing amount of KH-560. Benefiting from the abundant hierarchical structure, the Z5-X catalysts exhibited a larger coke capacity than the Z5 catalyst. The coke depositions of all the deactivated catalysts were characterized by the thermogravimetric technique (TG), and the results are indicative of the decreased average rate of coke deposition with an increasing amount of KH-560, which could result from the gradually reduced strong acid amount and the nano-sized crystallites. The catalytic performance of methanol-to-aromatics (MTA) indicates that the Z5-0.12 catalyst exhibited higher catalytic activity and selectivity of BTX as the reaction was prolonged, which could result from the synergistic effect among the proper strong acid amount, the smaller zeolite grain size, and the abundant hierarchical structure.
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PubMed
高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 6
·3013-3023
·
IF 4.21
Shen Feng,Sun Shuang,Zhang Xiao,Yang Jirui,Qiu Mo,Qi Xinhua
Abstract Direct production of the platform chemical 5-hydroxymethylfurfural (5-HMF) from cellulose is challenging due to the rigid structure of cellulose. Herein, 5-HMF was effectively obtained from cellulose with high loading concentrations (> 20 wt.%) via an Al 2 (SO 4 ) 3 -assisted mechanochemical method. The Al 2 (SO 4 ) 3 not only acted as catalyst for its Lewis and Brønsted acidity, but also assisted the disruption of the hydrogen bonds among cellulose molecules during ball milling pretreatment. The particle size and crystallinity of the cellulose greatly decreased after Al 2 (SO 4 ) 3 -assisted ball milling pretreatment. The effects of various factors, including the organic solvent, reaction temperature and time, catalyst dose, and substrate concentration, on the yield of 5-HMF from cellulose were studied. A yield of 5-HMF up to 43.5% was obtained from cellulose via the developed mechanochemical-assisted method. A 36.1% yield of 5-HMF was retained when the initial cellulose loading concentration was as high as 21.6 wt.%. The green and efficient mechanochemical-assisted method was applicable to the efficient coproduction of 5-HMF and furfural from several waste biomass feedstocks.
Graphic abstract
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JOURNAL OF CHEMICAL RESEARCH
·
2020
·
IF 0.593
Mingguang Zhang,Zhongbao Bi,Yunyun Wang,Yuxun Zhao,Yang Yang,Yongqiang Zhu,Shifa Wang
A new and practical synthesis of 3-chloro-2,4-difluoro-5-hydroxybenzoic acid, a key intermediate for preparing antimicrobial 3-quinolinecarboxylic acid drugs, is synthesized from 2,4-difluoro-3-chlororobenzoic acid. The protocol involves nitration, esterification, reduction of NO2, diazotization, and hydrolysis with a 70% overall yield. The structures of the synthesized compounds are determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution electrospray ionization mass spectrometry. The advantages of this developed synthetic strategy include an improved overall yield and readily controllable reaction conditions.
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JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 1
·1-14
·
IF 1.134
Jiang Yifei,Liu Yang,Fang Siyuan,Ji Min
In this study, a novel antitumor system was designed on the basis of photodynamic therapy and photothermal therapy using gold nanoshells coated 5-aminolevulinic acid (5-ALA) liposomes (GNALs). As a widely used photosensitizer prodrug, 5-aminolevulinic acid (5-ALA)-derived protoporphyrin
IX (PpIX) can accumulate to a higher level in tumors than in normal tissues. Protoporphyrin IX (PpIX) initiates a series of cytotoxic reactions after irradiation of target tissue with a measured dose of light with appropriate wavelength, which may be dependent on the generation of reactive
oxygen species. Gold nanoshells can strongly absorb NIR lasers at the same time, and can generate hyperthermia to provide photothermic effects. Gold nanoshells coated 5-ALA-Liposomes (GNALs) exhibit a uniform-sized spherical shape of 185.8±0.91 nm, with a zeta potential of 33±1.6
mV. Liposomes with specific sizes ranging from 100 to 200 nm can escape into the tumor interstitial tissue and accumulate preferentially in tumor tissue owing to the EPR effect. In addition, NIR light-excited nanosystems significantly promoted antitumor effects in this study compared to single
photodynamic therapy. It was also found that the increased temperature promoted inhibition rate of SKOV3 cells. The novel drug delivery system shows great potential in photothermal-photodynamic antitumor therapy.
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高影响因子
ADVANCES IN POLYMER TECHNOLOGY
·
2020
·
IF 1.539
Yunlong Liu,Jie Guo,Zhuobing Xiao,Dazhao Peng,Ke Song
Separation and purification of active components from biomass by inorganic materials during the pretreatment process of hydrothermal conversion are studied in this work. The batch experiment results show that an initial solution pH of 6 favors chelerythrine adsorption, and the optimum adsorbent dosage is 2.0 g. The adsorption mechanism of ZSM-5 for chelerythrine is investigated by adsorption kinetics, isotherm adsorption models, and thermodynamics analysis. The results show that the kinetics data fit the pseudo-second-order model well (R2 = 0.9991), and the intraparticle diffusion model has 3 diffusion stages, preliminarily indicating that chemisorption plays a major role in the adsorption process, and the sorption mechanism includes intraparticle, external, and boundary diffusion. The adsorption isotherms agree well with the Langmuir model, indicating the occurrence of monolayer molecular adsorption during the adsorption process. Meanwhile, the maximum adsorption capacity is 2.327, 2.072, and 1.877 mg/g at different temperatures (288 K, 298 K, and 308 K), respectively. The thermodynamic data demonstrate that the adsorption process is exothermic and spontaneous in nature. These observed results clearly confirm that ZSM-5 has potential superior properties for the enrichment and purification of alkaloids during the pretreatment of biomass.
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GREEN CHEMISTRY
·
2023
·Vol. 25
·期 20
·8196-8206
·
IF 9.8
Zhenchuan Zhang,Zhaohui Yang,Chenyang Wei,Zhenghui Liu,Tiancheng Mu
Metal oxide catalysts’ performance depends on their crystal structure, including the surface arrangement and coordination of metal cations and oxygen anions on the exposed facets. Here, we fabricated Co3O4 nanocrystals (NCs) with predominantly exposed (110), (111), (112), and (114) facets in the shapes of nanorod (Co-R), hexagonal nanoplate (Co-H), nanolaminar (Co-L), and nanoparticle (Co-P), respectively. The Co3O4 NC with exposed (114) high-index facet exhibits the highest 5-hydroxymethylfurfural (HMF) electrocatalytic activity, while the Co3O4 NC with exposed (112) shows the lowest activity. Both density functional theory (DFT) calculations and experiments reveal that the primary factor impacting the catalytic performance of Co3O4 NCs is the difference in HMF adsorption energy on various crystal facets. By doping Cr into Co3O4 (114), we tuned the adsorption energy of HMF to an optimal level, thereby achieving the best catalytic performance. Based on this, the adsorption behavior of other aldehyde–alcohol organic small molecules was also evaluated, and the linear relationship between adsorption strength and catalytic activity was confirmed. This work demonstrates that adjusting the exposed crystal facets of Co3O4 can alter the adsorption and catalytic capabilities of aldehyde–alcohol organic small molecules. It also provides explicit knowledge that could improve our understanding of facet-dependent reactions for other metal oxide catalysts.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Kezhen Qian,Wenmin Tian,Lijie Yin,Zixu Yang,Feixiang Tian,Dezhen Chen
The nature of Zn species and their roles in catalytic cracking of high-density polyethylene (HDPE) thermal decomposing vapor over Zn-promoted HZSM-5 (Zn/Z5) for aromatics were investigated. The Zn/Z5 zeolites were prepared using ion exchange and impregnation methods followed by H 2 reduction. Results indicated that hydrogen reduction of the Zn/Z5 significantly improved the aromatic yield. [ZnOH] + and bridged Zn 2+ species were critical species promoting BTX formation, with the former demonstrating higher activity. Besides, the synergistic effect between the Zn species and Brønsted acid sites on HZSM-5 boosts the aromatic yield. Incorporation of Zn was also found to promote long-chain scission. Among all the Zn/Z5, hydrogen reduced 2 wt% Zn/Z5 (SAR=25) is most effective in producing BTX, with a maximum yield of BTX (48%) and BTX selectivity (93%); hydrogen reduced 2 wt% Zn/Z5 (SAR=50) produced the highest yield of total aromatics (53%).
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NEUROENDOCRINOLOGY
·
2023
·Vol. 113
·期 6
·641-656
·
IF 4.1
Zheng Biaolin,Chen Xiubing,Chen Fengping,Liao Xiaomin,Wang Feng,Yang Zhe,Yi Nan,Shi Xiaoyan,Qin Shanyu,Jiang Haixing
Introduction: 5-Iodotubercidin, a type of purine derivative, has attracted increasing attention in tumor chemotherapy because of its potential as an antitumor agent in recent years. In this study, we confirmed the effects on apoptosis in insulinoma cell lines induced by 5-iodotubercidin and tried to illuminate the underlying mechanisms. Methods: We used 5-iodotubercidin in the treatment of insulinoma cells and the cell proliferation was examined using CCK-8 assay, colony-forming assays, and insulinoma animal models. Cell apoptosis was examined using TUNEL assays and Western blotting. Cellular DNA damage was shown by comet assay and immunofluorescence. The expression of apoptosis-regulating proteins and DNA damage biomarker was investigated by Western blotting. Subcutaneous inoculation of the insulinoma cells into nude mice was to measure blood glucose, insulin levels, and tumor growth. ATM siRNA and p53 siRNA were used as loss-of-function targets to evaluate 5-iodotubercidin treatment. Results: 5-Iodotubercidin inhibited the proliferation of insulinoma cells and induced DNA damage and cell apoptosis. Moreover, 5-iodotubercidin induced ATM and p53 activated. In vivo, 5-iodotubercidin inhibited the growth of Ins-1 and Min-6 cells xenografts in nude mice. Conclusion: 5-Iodotubercidin induces DNA damage leading to insulinoma cells apoptosis by activating ATM/p53 pathway. Therefore, this is a potential strategy for treating insulinoma
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