ACS Sustainable Chemistry & Engineering
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2020
·
IF 7.632
Shuang Sun,Lijie Zhao,Jirui Yang,Xiaoqi Wang,Xiaoya Qin,Xinhua Qi,Feng Shen
A green, efficient, and facile ball-milling-assisted strategy was proposed to design an SO3H-containing solid acid for biomass valorization, where −SH groups were grafted on a natural clay attapulgite by wet ball milling with 3-mercaptopropyltrimethoxysilane (MTPS), followed by the oxidation of −SH to −SO3H with H2O2 at room temperature. The mechanism of the −SO3H functionalization by the ball-milling process was investigated, and the investigation indicated that the MTPS was grafted on the attapulgite through hydrolysis and condensation, which was induced by the mechanical forces of ball milling. Characterization, including SEM, EDX (energy-dispersive X-ray spectrometry), NH3-TPD, TGA, FT-IR, elemental analysis, and XPS, confirmed the success of −SO3H modification on attapulgite with a total acidity of 1.81 mmol/g. Harsh conditions involving a corrosive sulfonating agent, organic solvent, or high temperature in traditional methods are avoided in the developed approach. The prepared catalyst displayed a high activity toward the transformation of biomass-derived carbohydrates (glucose, fructose, cellobiose, sucrose, starch, and cellulose) into the more valuable chemical 5-hydroxymethylfurfural due to the synergy effect of MgO and −SO3H sites on the catalyst. Moreover, the catalyst showed excellent stability and recyclability for five recycles without loss of activity. This study provides a novel green method for the preparation of an SO3H-containing heterogeneous catalyst, which should have great application potential in other processes of biomass valorization.
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TALANTA
·
2020
·
IF 5.339
Liang Fu,Qijing Lu,Xianlin Liu,Xiaogang Chen,Xiang Wu,Shusen Xie
Lead ions are deleterious pollutants that often reach drinking water, and can cause significant harm to humans (particularly children). An ultra-sensitive lead ion detection method using a whispering gallery mode (WGM) optofluidic microbubble resonator and the classic GR-5 DNAzyme is proposed in this paper. With the auxiliary piranha and Ploy- l -lysine solution, GR-5 DNAzyme was successfully modified on the inner wall of a microbubble. The mode field distribution of the microbubble was analysed, and the optofluidic sensor with thin wall exhibited a maximum bulk refractive index sensitivity of 265.2 nm/RIU. Lead ions at concentrations ranging from 0.1 pM to 100 pM were tested using the proposed WGM optofluidic sensor. The noise was decreased to 2.43 fM using the self-referenced differential method. Thus, a limit of approximately 15 fM was obtained for the detection of lead ions using the WGM optofluidic biosensor. Eight competing metal ions were also used to evaluate the selectivity of the proposed sensor, with results indicating that it has high selectivity for lead ions. Finally, the sensor performance is verified using real samples.
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CHEMOSPHERE
·
2020
·
IF 5.778
Xingtao Zuo,Cheng Qian,Senlin Ma,Juan Xiong
Sulfonamides (SAs) in the aquatic environment are a serious threat to human health, environmental ecology and water reuse . Natural organic matter and SAs are known to compete for adsorption sites on adsorbent. SAs adsorption by high silica ZSM-5 (HSZSM-5) affected by humic monomers remains unclear. The impact of representative humic monomers (HMs) (caffeic acid (CA) and vanillin (VNL)) on the sorption of SAs by HSZSM-5 at different pH was evaluated for the first time. Fourier transform infrared and X-ray photoelectron spectroscopy were used to obtain the group transformations. The presence of HM did not change the main adsorption mechanism of SAs on pristine and loaded HSZSM-5 (pH-dependent and hydrophobic interaction). Lewis acid-base electron interaction , π-π electron donor-acceptor (EDA), and H-bonding had a positive contribution to the adsorption of SAs by HSZSM-5 after HM coating. However, HM coating and competition reduced the adsorption capacity of HSZSM-5 towards SAs. In co-introduction system of HM and SAs, the reaction between C O in HM and N–H in SAs resulted in SAs and HM co-adsorbed on HSZSM-5. Meanwhile, CA concentration <20 mg/L was in favor of SMX adsorption. The findings give an insight into the interactions among HM and SAs in high silica zeolites adsorption system, thereby improving SAs removal in actual water.
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CATALYSIS TODAY
·
2020
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IF 5.825
Hong Du,Miao Jiang,Xiuyun Ma,Peifang Yan,Z. Conrad Zhang
The rapid consumption of fossil resources and the grim environmental situation encourage the application of renewable and clean energy resources. Conversion of biomass, which is a kind of renewable, CO 2 neutral as well as abundant reserves carbon containing resource, is significantly important. The production of fuels from biomass by means of gasification and Fischer-Tropsch synthesis is one of the most promising routes for industrial applications. The wax-free liquid fuels synthesis directly from H 2 -deficient syngas similar to bio-gas is highly advantageous for reducing investment and operating cost. Thus, the Mn-promoted meso-ZSM-5 supported cobalt catalyst was applied for the production of wax-free liquid fuels by catalytic H 2 -deficient syngas conversion in this study. The performance of the reaction was influenced obviously by Mn content. The cobalt dispersion increased with the addition of Mn, whereas the reduction degree decreased after Mn doping. Then, the balance between the dispersion and reduction degree led to the change in CO uptake followed a volcanic curve. The catalyst with moderate amount of Mn (1 wt%) had the suitable cobalt particle size and the maximum CO uptake. Thus, the highest CO conversion was obtained over Co-1Mn/meso-ZSM-5 catalyst thanks to its maximum exposed active sites. The appropriate amount of Mn addition also resulted in the decreasing of CH 4 selectivity. The highest space time yield of liquid fuels was acquired over the Co-1Mn/meso-ZSM-5 catalyst from H 2 -deficient syngas conversion under the moderate conditions.
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TALANTA
·
2020
·
IF 5.339
Chengji Sui,Qian Wang,Yunlei Zhou,Dingding Zhang,Huanshun Yin,Shiyun Ai
A sensitively homogeneous electrochemiluminescence (ECL) method was developed for 5-hydroxymethylcytosine (5hmC) detection using TiO 2 /MoS 2 /g-C 3 N 4 /GCE as substrate electrode, where g-C 3 N 4 was employed as the ECL active material, the MoS 2 nanosheets were used as co-catalyst, and TiO 2 was adopted as phosphate group capture reagent. To achieve the specific recognition and capture of 5hmC, the covalent reaction between –CH 2 OH and –SH was employed under the catalysis of HhaI methyltransferase, in which, –SH functionalized ferrocenedicarboxylic acid polymer (PFc-SH) was prepared as 5hmC capture reagent and ECL signal quencher. Then, based on the interaction between TiO 2 and phosphate group of 5hmC, the target was recognized and captured on electrode, resulting in a decreased ECL response due to the quenching effect of PFc-SH. Under optimal conditions, the biosensor presented the linear range from 0.01 to 500 nM with the detection limit of 3.21 pM (S/N = 3). The steric effect on electrode surface is a bottle-neck issue restricting devised biosensors advancement. In this work, the reaction between 5hmC and PFc was carried out in the solution, which can avoid steric effect on electrode surface to keep the high activity of enzyme. In addition, the biosensor was successfully applied to detect 5hmC in genomic DNA of chicken embryo fibroblast cells and different tissues of rice seedlings.
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Biotechnology for Biofuels
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2020
·Vol. 13
·期 1
·1-13
·
IF 4.815
Chen Jiuzhou,Wang Yu,Guo Xuan,Rao Deming,Zhou Wenjuan,Zheng Ping,Sun Jibin,Ma Yanhe
Background 5-Aminolevulinic acid (5-ALA) is a promising biostimulant, feed nutrient, and photodynamic drug with wide applications in modern agriculture and therapy. Considering the complexity and low yield of chemical synthesis methods, bioproduction of 5-ALA has drawn intensive attention recently. However, the present bioproduction processes use refined glucose as the main carbon source and the production level still needs further enhancement.Results To lay a solid technological foundation for large-scale commercialized bioproduction of 5-ALA, an industrial workhorse Corynebacterium glutamicum was metabolically engineered for high-level 5-ALA biosynthesis from cheap renewable bioresources. After evaluation of 5-ALA synthetases from different sources, the 5-ALA biosynthetic pathway and anaplerotic pathway were rebalanced by regulating intracellular activities of 5-ALA synthetase and phosphoenolpyruvate carboxylase. The engineered biocatalyst produced 5.5 g/L 5-ALA in shake flasks and 16.3 g/L in 5-L bioreactors with a one-step fermentation process from glucose. To lower the cost of feedstock, cheap raw materials were used to replace glucose. Enzymatically hydrolyzed cassava bagasse was proven to be a perfect alternative to refined sugars since the final 5-ALA titer further increased to 18.5 g/L. Use of corn starch hydrolysate resulted in a similar 5-ALA production level (16.0 g/L) with glucose, whereas use of beet molasses caused seriously inhibition. The results obtained here represent a new record of 5-ALA bioproduction. It is estimated that replacing glucose with cassava bagasse will reduce the carbon source cost by 90.1%.Conclusion sThe high-level biosynthesis of 5-ALA from cheap bioresources will brighten the prospects for industrialization of this sustainable and environment-friendly process. The strategy for balancing metabolic flux developed in this study can also be used for improving the bioproduction of other value-added chemicals.
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Journal of the Taiwan Institute of Chemical Engineers
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2020
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IF 4.794
Xiaowei Fang,Ze Wang,Wenli Song,Songgeng Li
In this paper the aldol condensation of furfural (C5) with acetone (C3) over Ca/ZSM-5 was studied with lower dosages of water and acetone as compared to previous studies. It was observed that the formation of CaO over the catalyst is critical to catalyst activity and that the reaction may not occur without water. Although higher quantity of water was favorable for the formation of 4-(2-Furyl)-3-buten-2-one (C8), it was inhibitive for the formation of 1,5-bis-(2-furanyl)-1,4-pentadien-3-one (C13). Highest yields of C8 (38.4 mol%) and C13 (60.2 mol%) were obtained with C3-to-C5 mole ratio of 0.8:1, and water content of 29.7 wt%. The deactivated catalyst was further regenerated by re-loading CaO. An intrinsic kinetic model was established whereby the reaction was first-order dependent on the concentration of each reactant. The formation of 4-(2-furyl)-4‑hydroxy‑butan-2-one (C8-OH), and the C8-OH-to-C8 dehydration were essential steps. The reaction of C8-OH with C5 owned the highest activation energy (41.9 kJ/mol), this step was more sensitive to reaction temperature than those of other steps.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Chunhao Guo,Yang Tang,Jinru Wan,Yue Zuo,Yong Wang,Yichang Wang,Xunqiu Wang
The isobaric vapour–liquid equilibrium (VLE) data for the binary system of cyclohexanol + cyclohexylbenzene were determined at (5, 10, 15, 20 and 25) kPa with a dynamic recirculating apparatus and the temperature ranged from 358.10 K to 456.43 K, and the thermodynamic consistency of the experimental data was checked by the Herington area method and Van Ness method. Afterwards, the experimental data was correlated with NRTL, Wilson and UNIQUAC model, and the corresponding interaction of thermodynamic models of the binary system parameters were obtained through the Aspen software. The results indicated that all three models represent the experimental values quite well, while the NRTL model provided a slightly better result than Wilson model and UNIQUAC model. The maximum root mean square deviation of the temperature and vapour phase mole fraction for the NRTL model was less than 0.4 K and 0.004, respectively.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2020
·
IF 4.192
Xiaofeng Zhang,Xinqi Xu,Xuemei Yao,Rong Wang,Hengtao Tang,Xin Ju,Liangzhi Li
Ribose-5-phosphate isomerase B is of great importance for biocatalysis and biosynthesis, but the multifunctional residues in active sites hinder the research efforts. This study employed rational design strategies to locate the key residues of RpiB from Ochrobactrum sp. CSL1 (OsRpiB). A single-mutant S9T of a noncontact residue showed 80% activity improvement toward d-allose. A double-mutant S98H/S134H further increased the activity to 3.6-fold. The mutations were analyzed by kinetics and molecular dynamics analyses, indicating that S9T might enhance the substrate binding and catalysis by inducing a steric effect, and S98H/S134H could strengthen both ring opening and binding of d-allose. Though S98H/S134H showed low temperature stability, its potential was explored by isomerizing d-allose to d-psicose with higher conversion and in less reaction time. The findings of this study were beneficial for illustrating the complex functions of key residues in RpiBs and applying OsRpiB in preparing rare sugars.
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高影响因子
Biomass Conversion and Biorefinery
·
2020
·Vol. 11
·期 5
·1931-1941
·
IF 2.602
Tian Xiatian,Qi Benkun,Zhang Shaofeng,Luo Jianquan,Wan Yinhua
5-Hydroxymethylfurfural (HMF) is a promising platform chemical for production of value-added chemicals and fuels. Conversion of abundantly available and cheap sucrose for HMF synthesis was systematically investigated in the present study. Results showed that Lewis acid AlCl 3 is effective in catalytic transformation of sucrose. Combining AlCl 3 with different Brønsted acids, no matter whether they were inorganic acids (HCl, H 2 SO 4 , and H 3 PO 4 ) or organic acids (malic acid, succinic acid, and oxalic acid), or variation of ratio of Lewis acid/Brønsted acid represented by AlCl 3 /HCl, did not change the obtained maximum HMF yields compared with AlCl 3 alone, but shortened the time required to reach the maximum HMF yield. Sucrose conversion in a green reaction media of aqueous γ-valerolactone (GVL) solvent resulted into comparable HMF yields with dimethyl sulfoxide (DSMO)-water system. Addition of monovalent salt NaCl and divalent salt Na 2 SO 4 produced opposite effect with Cl − promoting while SO 4 2− inhibiting HMF production. Furthermore, HMF synthesis from constituent monosaccharides of sucrose and molasses, a by-product from sugar manufacturing process, was also carried out and it was found that an equivmole mixture of glucose and fructose gave rise to almost identical HMF yield to the same mole of sucrose. Molasses, even after chemical pretreatment for removal of certain amount of inorganic salts and color substances, was significantly inferior to synthetic molasses in terms of HMF formation, indicating the complexity and difficulty in chemical valorization of molasses for production of platform molecules.
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FUEL
·
2021
·
IF 6.609
Chengyang Cao,Huimin Liu,Dan Zhang,Kai Zhu,Aijun Li,Linling Wang,Hongyun Hu
Coolant additives are commonly used to offset the excessive combustion temperature of 5-aminotetrazole (5-AT) based solid propellants. However, the discrepancy of the burn-rate reduction by different coolants has been observed, restricting the precise control of 5-AT propellant’s combustion behavior. The focus of the current study is the effect of two metal oxides (Al 2 O 3 and MgO), produced by the endothermic decomposition of coolants (Al(OH) 3 and MgCO 3 ), on the decomposition mechanism and kinetic behavior of 5-AT. Results showed that these two additives impact the decomposition of 5-AT above 310 °C, focusing on the formation and decomposition of condensation products (melamine, melem, and melon-like). It revealed that the polymer layer thickness increased by Al 2 O 3 but decreased with MgO, which directly influenced the gas evolution process and heat transfer process. Kinetic calculation using the advanced Vyazovkin method and standard Criado method confirmed the catalytic decomposition of condensation products over the metal oxides’ surface. The reaction model changed from the reaction order model (Fn) to the geometrical model (Rn). Scheme and mechanism of the decomposition of 5-AT at separated stages were proposed. The findings of this study could contribute to understanding the burn-rate reduction mechanism of coolants and benefit the design of composite coolants used in 5-AT based propellants.
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NANOTECHNOLOGY
·
2021
·Vol. 32
·期 45
·455101
·
IF 3.874
Xiaojing Yang,Di-Feng Chen,Lin-Song Li,Xue-Jie Zhao,Mei-Xia Zhao
In this study, a nanodrug carrier (mesoporous silica nanoparticle (MSN)-SS-cysteamine hydrochloride (CS)-hyaluronic acid (HA)) for targeted drug delivery was prepared using MSNs, in which HA was used as a targeting ligand and blocking agent to control drug release. Coumarin is a fluorescent molecule that targets mitochondria. Two conjugates (XDS-DJ and 5-FUA-4C-XDS) were synthesized by chemically coupling nitrogen mustard and 5-fluorouracil with coumarin, which was further loaded into MSN-SS-CS-HA nanocarriers. MTT analysis demonstrated that the nanocomposite MSN-SS-CS@5-FUA-4C-XDS/HA displayed stronger cytotoxicity toward HCT-116 cells than HeLa or QSG-7701 cells. Furthermore, MSN-SS-CS@5-FUA-4C-XDS/HA was able to target the mitochondria of HCT-116 cells, causing decreased mitochondrial membrane potential and excessive production of reactive oxygen species. These results indicate that MSN-SS-CS@5-FUA-4C-XDS/HA has the potential to be a nanodrug delivery system for the treatment of colon cancer.
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