APPLIED ENERGY
·
2018
·
IF 7.9
Yuan Zhang,Yong Wang,Hongyou Cui,Pingping Zhao,Feng Song,Xiuyu Sun,Yujiao Xie,Weiming Yi,Lihong Wang
Conversion of the carboxylic acids in bio-oil into ketones via decarboxylation is a highly efficient approach for bio-oil upgrading. However, the char formation during decarboxylation is due to the existence of a considerable amount of pyrolytic sugars in bio-oil, which severely weakens the upgraded bio-oil yield and the energy efficiency. In this paper, two pretreatment approaches, hydrolysis and oxidative hydrolysis, were employed to solve this problem. The pyrolytic sugars in bio-oil were firstly enriched into the water-soluble fraction through water extraction, followed by hydrolysis or oxidative hydrolysis pretreatment before decarboxylation. With the aid of hydrolysis pretreatment, the upgraded bio-oil yield was increased from 27.55 to 30.74%, and the energy efficiency was increased from 77.59 to 88.67% after decarboxylation, whereas the char yield was decreased from 5.67 to 3.81% in comparison with the results without hydrolysis. In the case of oxidative hydrolysis pretreatment, the upgraded bio-oil yield and the energy efficiency were further enhanced to be 32.68% and 92.70% respectively, while the char yield was drastically decreased to only 1.15%. To clarify the effect of the pretreatment, two pentoses and four hexoses were used to investigate the reaction pathways for their conversion in the water-soluble fraction during hydrolysis or oxidative hydrolysis pretreatment. The experimental results showed that hydrolysis of the water-soluble fraction could effectively convert pyrolytic sugars to carboxylic acids. In contrast, oxidative hydrolysis could convert not only the pyrolytic sugars, but also most of the aldehydes and ketones in the water-soluble fraction into carboxylic acids. The reaction pathways for conversion of pentose and hexose into organic acids via oxidative hydrolysis were also investigated.
研究领域:
生物质能
·
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Juntao Tang,Xinlong Wang,Yusheng Huang,Xiaopeng Du,Zhiqiao He,Da Wang,Shuang Song
The relatively weak activity and serious deactivation of anatase TiO 2 nanosheet catalysts with highly exposed {0 0 1} facets ({0 0 1}-TiO 2 ) limits its wide application in photocatalytic degradation of gaseous pollutants. Herein, we propose a hybrid photocatalyst composed of {0 0 1}-TiO 2 and SiO 2 with numerous hydroxyl groups (denoted as {0 0 1}-TiO 2 /HO-SiO 2 ). The catalyst showed excellent performance for gaseous toluene degradation under UV illumination, with 99.2 % removal efficiency and 204.7 μmol L −1 CO 2 yield (about 85.9 % mineralization efficiency) within 120 min. It also demonstrated superior durability over five consecutive cycles of toluene photodegradation. The modification of HO–SiO 2 on {0 0 1}-TiO 2 facilitate the selective adsorption of toluene on the catalyst surface by H-bonding interaction, and make the major poisoning species, benzoic acid, easily desorb from the surface, reducing the catalyst inactivation. Most importantly, we found that the formed Ti O Si bond promotes the separation of photogenerated electron–hole pairs, and provides abundant available electrons for the formation of reactive oxygen radicals and the left holes for the conversion of toluene to benzyl radicals or oxidation of H 2 O to hydroxyl radicals, which results in the improved activity. This study highlights the importance of the introduction of secondary components with special functions on TiO 2 , which is helpful for the design of photocatalysts with high performance and anti-deactivation ability for treatment of volatile organic compounds.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Xiangquan Qin,Yiping Jiang,Jie Chen,Fuquan Yao,Longyi Jin,Zhiqi Cong
Selective hydroxylation of C( sp 3 )–H bonds is a long-standing challenge in the organic synthesis field. We herein report an artificial P450 peroxygenase system facilitated by ω-pyridyl fatty acyl amino acids that can hydroxylate broad-spectrum alkanes, including linear and cyclic alkanes and benzylic and allylic alkane chains. Compared with the previously reported dual-functional small molecule (DFSM) with imidazole as a catalytic group (Im-DFSM), pyridyl DFSM (Pyd-DFSM) produced substantially higher total turnover numbers (TTNs) for the hydroxylation of medium-chain alkanes and cycloalkanes (C6–C8), e.g., 12.0-fold and 17.1-fold increased TTNs of P450 mutant F87A/T268V for heptane and cycloheptane , respectively. In addition, Pyd-DFSM altered the enantioselectivity of benzylic hydroxylation, e.g., it almost inverted the configuration observed in the benzylic hydroxylation of ethylbenzene and tetralin . More importantly, Pyd-DFSM showed excellent regioselectivity for allylic hydroxylation over epoxidation of terminal alkenes and cycloalkenes , e.g., up to 94% allylic hydroxylation of 1-hexene was observed. This work significantly enhances the catalytic toolbox of the DFSM-facilitated P450 peroxygenase system; it not only substantially expands the chemical space of P450 enzymes, but also provides an alternative solution for the selective hydroxylation of C( sp 3 )–H bonds.
研究领域:
有机化学
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生物化学
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催化
·
酶工程
✓ 已验证
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 3
·564
·
IF 5
Huafen Wang,Huanhuan He,Jiaxiang Zhang,Juntao Liu,Yuwei Zhuang,Yuanyuan Yin,Zhiyong Ren,Yang Fu,Suqin He
Novel monomethoxy poly(ethylene glycol) (mPEG) modified hydroxylated tung oil (HTO), denoted asmPEG-HTO-mPEG, was designed and synthesized for drug delivery.mPEG-HTO-mPEG consists of a hydroxylated tung oil center joined by twomPEG blocks via a urethane linkage. The properties ofmPEG-HTO-mPEG were affected by the length of the mPEG chain. ThreemPEG with different molecular weights were used to preparemPEG-HTO-mPEG. The obtained threemPEG-HTO-mPEG polymers were characterized by nuclear magnetic resonance (NMR), Fourier transformation infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC), respectively. Furthermore, the particle sizes ofmPEG-HTO-mPEG micelles were evaluated by dynamic light scattering (DLS) and transmission electron microscope (TEM). A critical aggregation concentration (CAC) ranged from 7.28 to 11.73 mg/L depending on the chain length of mPEG. The drug loading and release behaviors ofmPEG-HTO-mPEG were investigated using prednisone acetate as a model drug, and results indicated that hydrophobic prednisone acetate could be effectively loaded intomPEG-HTO-mPEG micelles and exhibited a long-term sustained release. Moreover, compared with HTO,mPEG-HTO-mPEG had no obvious cytotoxicity to HeLa and L929 cells. Therefore, monomethoxy poly(ethylene glycol) modified hydroxylated tung oilmPEG-HTO-mPEG may be a promising drug carrier.Keywords:hydroxylated tung oil;poly(ethylene glycol);drug delivery
研究领域:
材料科学
·
药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Yan Li,Bing Li,Ting Chen,Zhicheng Zhou,Jun Wang,Jun Huang
A vanadium doped graphitic carbon nitride catalyst has been prepared and used for the direct hydroxylation of arenes with O 2 . Substituted arenes with electron-withdrawing groups such as CN, NO 2 , COOH, CF 3 , and COCH 3 were oxygenated to the corresponding phenols in moderate yields. The catalyst also proved applicable for the hydroxylation of aromatic halides (F, Cl, and Br) with O 2 .
研究领域:
化学
·
催化科学
✓ 已验证
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 2
·261
·
IF 3.426
Yu Ji,Qiang Yao,Weihong Cao,Yueying Zhao
The intumescent process of sodium (substituted) phenolates has been studied. The generation of hydrogen radical via a homolytic cleavage of the Ar–H bond and the subsequent hydroarylation of phenolates to cyclohexadienes along with cyclization and elimination reactions of cyclohexadienes are critical steps in the base promoted intumescence of phenols. The substituents show great influence on the intumescence of phenolates. Phenolates substituted with a weak electron donating group enable intumescence while those with an electron withdrawing group or strong electron donating group suppresses intumescence. This distinction can be justified by both electronic and steric effects of substituents on the generation of hydrogen radical and the degree of hydroarylation.Keywords:alkali;intumescence;substituent;hydroarylation;phenolate
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Zhiming Ding,Yaheng Zhang,Jian Ruan,Chuanting Fan,Runjuan Du,Jie Zhang,Zhiyong Tang
Electrophotocatalytic C-H hydroxylation of benzene is an emerging green technology with high potential for producing phenol in one step. However, it is still limited by efficiency and scale-up challenges in batch process. In this study, a novel electrophotochemical flow microreactor was designed and manufactured using 3D printing technology. Static mixers were incorporated to enhance the mixing. The effect of various parameters, such as electrode materials, reaction time, potential, and reactant concentration, etc., on the continuous synthesis of phenol in the as-developed microreactor was investigated. Furthermore, machine learning (ML) algorithms were employed to explore the impact of these parameters on the reaction efficiency. With cost-effective electrodes, higher phenol productivity was achieved in the present flow microreactor when comparing with batch counterpart and literature value. This study offers insights into the optimization of electrophotochemical microreactor for the hydroxylation of benzene, and provides guidance for exploring sustainable electrophotocatalytic organic synthesis in flow.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Lixin Kang,Haoran Li,Kexin Lin,Shen Hu,Song Liu,Yuben Qiao,Ying Wang,Aitao Li
The biocatalytic production of 25-hydroxyvitamin D3 (25(OH)VD3, calcidiol) represents a superior alternative to traditional chemical synthesis. However, the reported VD3 hydroxylases generally exhibit suboptimal catalytic efficiency, limiting their practical applications. In this study, a cytochrome P450 CYP107Pdh from Pseudonocardia dioxanivorans_CB1190, which displays unique C26 hydroxylation activity on VD3, was identified. Then, structure-guided loop engineering combined with binding pocket reshaping was conducted on CYP107Pdh, leading to the generation of the quintuple variant 89_90insIP/T112A/V161L/G186V (M4). This variant shifted the regioselectivity from 91% C26 in the wild type (WT) to 81% C25 for calcidiol production. In addition, variant M4 showed a remarkable enhancement in catalytic activity, achieving a catalytic efficiency (kcat/Km) that is 75-fold higher than that of the WT. Computational analyses revealed that the regioselectivity shift and activity improvement are primarily attributed to a conformational transition in the substrate-binding pocket from an open to a more closed state, which optimizes substrate binding and facilitates efficient 25-hydroxylation of VD3. Finally, a semipreparative biotransformation yielded 2.64 g of crystalline calcidiol (95% purity) from a 1-L reaction, thereby expanding the enzyme library of VD3 hydroxylases and underscoring its potential for industrial-scale production of calcidiol.
研究领域:
生物化学
·
酶工程
·
药物合成
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2015
·
IF 4.494
Shengnan Shi,Yuanyuan Qu,Hao Zhou,Qiao Ma,Fang Ma
Arthrobacter sp. W1 was used to characterize the pathways involved in cometabolic degradation of carbazole (CA) with phenol as the primary substrate. To clarify the upper pathway of cometabolic degradation CA, Escherichia coli strain BL21 expressing phenol hydroxylase from strain W1 (PH IND ) was investigated to degrade CA. Firstly, CA was initially monohydroxylated at C-2 and C-4 positions to produce 2- and 4-hydroxycarbazole, followed by successively hydroxylated to the corresponding 1,2- and 3,4-dihydroxycarbazole, of which 3,4-dihydroxycarbazole was unequivocally identified for the first time. To characterize the downstream cometabolic degradation CA pathway, purified 3,4-dihydroxycarbazole was used as the substrate for phenol-grown W1, and a series of novel indole derivatives were identified. These results suggested that a novel pathway of CA catabolism was employed by strain W1 via a successive hydroxylation and meta -cleavage pathway. These findings provide new insights into the cometabolic degradation CA process and have potential applications in biotechnology and bioremediation.
研究领域:
微生物学
·
环境科学
·
生物技术
✓ 已验证
DOI
高影响因子
CHEMISTRY & BIODIVERSITY
·
2021
·Vol. 18
·期 4
·e2000910
·
IF 2.408
Bingbing Ma,Qianwen Wang,Bing-Nan Han,Haruo Ikeda,Chunfang Zhang,Lian-Hua Xu
Cytochrome P450 enzymes (P450s) are versatile biocatalysts, which insert a molecular oxygen into inactivated C−H bonds under mild conditions. CYP105D7 from Streptomyces avermitilis has been reported as a bacterial substrate-promiscuous P450 which catalyzes the hydroxylation of 1-deoxypentalenic acid, diclofenac, naringenin, compactin and steroids. In this study, CYP105D7 catalyzes hydroxylation, epoxidation and dehydrogenation of capsaicin, a pharmaceutical agent, revealing its functional diversity. The kinetic parameters of the CYP105D7 oxidation of capsaicin were determined as K m =311.60±87.30 μM and k cat =2.01±0.33 min −1 . In addition, we conducted molecular docking, mutagenesis and substrate binding analysis, indicating that Arg81 plays crucial role in the capsaicin binding and catalysis. To our best knowledge, this study presents the first report to illustrate that capsaicin can be catalyzed by prokaryotic P450s.
研究领域:
生物化学
·
药物代谢
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2011
·
IF 3.384
Hua Yang,Jia-Qi Chen,Jun Li,Ying Lv,Shuang Gao
Hydroxylation of benzene to phenol in the [(CH 3 ) 4 N] 4 PMo 11 VO 40 /ascorbic acid/TEMPO/O 2 catalytic system was carefully investigated. UV–vis, ESR and 1 H NMR studies showed ascorbic acid radicals were formed through the hydrogen exchange of ascorbic acid with TEMPO (2,2,6,6-tetramethyl-1-piperidine-N-oxyl radicals) during the reaction. In acetonitrile, the ascorbic acid would be partly oxidized to 2-hydroxy-2-buten-4-olide (α-tetronic acid, isotetronic acid, compound 1 ) without TEMPO. The interaction of TEMPO and ascorbic acid restrained the oxidative dissociation of ascorbic acid and promoted the rate of the hydroxylation. Aqueous acetic acid solvent can also restrain the oxidative dissociation of ascorbic acid. In aqueous acetic acid, the yield of phenol could reach 18.9% in the [(CH 3 ) 4 N] 4 PMo 11 VO 40 /ascorbic acid/TEMPO/O 2 catalytic system with sufficient ascorbic acid after 400 min.
研究领域:
催化化学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2019
·
IF 3.973
Cijun Shuai,Guofeng Liu,Youwen Yang,Wenjing Yang,Chongxian He,Guoyong Wang,Zheng Liu,Fangwei Qi,Shuping Peng
Piezoelectric effect of polyvinylidene fluoride (PVDF) plays a crucial role in restoring the endogenous electrical microenvironment of bone tissue, whereas more β phase in PVDF leads to higher piezoelectric performance. Nanoparticles can induce the nucleation of the β phase. However, they are prone to aggregate in PVDF matrix, resulting in weakened nucleation ability of β phase. In this work, the hydroxylated BaTiO 3 nanoparticles were functionalized with polydopamine to promote their dispersion in PVDF scaffolds fabricated via selective laser sintering. On one hand, the catechol groups of polydopamine could form hydrogen bonding with the hydroxyl groups of the BaTiO 3 . On the other hand, the amino groups of polydopamine were able to bond with C F group of PVDF. As a result, the functionalized BaTiO 3 nanoparticles homogeneously distributed in PVDF matrix, which significantly increased the β phase fraction from 46% to 59% with an enhanced output voltage by 356%. Cell testing confirmed the enhanced surface electric cues significantly promoted cell adhesion, proliferation and differentiation. Furthermore, the scaffolds exhibited enhanced tensile strength and modulus, which was ascribed to the rigid particle strengthening effect and the improved interfacial adhesion. This study suggested that the piezoelectric scaffolds shown a potential application in bone repair.
研究领域:
生物医学工程
·
材料科学
✓ 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）