APPLIED CATALYSIS B-ENVIRONMENTAL
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2013
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IF 5.825
Xing Tang,Huawei Chen,Lei Hu,Weiwei Hao,Yong Sun,Xianhai Zeng,Lu Lin,Shijie Liu
A series of low-cost readily-assembled eco-friendly metal hydroxides were examined as catalysts in the synthesis of a novel platform molecule, γ-valerolactone (GVL), from biomass-derived ethyl levulinate (EL) via hydrogen transfer reaction. Among these catalysts, ZrO(OH) 2 · x H 2 O was found to be most active. EL conversion of 93.6% and GVL selectivity of 94.5% were achieved when 2-propanol was used as a hydrogen donor at 473 K with a reaction time of only 1 h. The complete reaction pathway and the probable main by-products for the conversion of EL to GVL were clearly deduced for the first time. The ZrO(OH) 2 · x H 2 O catalyst could be reused at least ten times without any significant loss of catalytic activity. Furthermore, characterizations were carried out on the fresh and spent ZrO(OH) 2 · x H 2 O catalysts with XRD, FT-IR, BET, TGA-DTA. Combined with the results of poisoning experiments, a plausible mechanism for catalytic transfer hydrogenation (CTH) of EL to GVL was proposed to be consisted of a catalytic cycle involving a six member ring transition state.
研究领域:
化学工程
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催化
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绿色化学
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可再生能源
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产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2023
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IF 9.1
Ge Tang,Kuaqian Deng,Panyang Li,Jiali Huang,Fanglin Dao,Hao Jiang,Jing Wang,Jianfang Jiang
Carrier, immobilization method and conditions are the most important factors affecting the performance of immobilized lipase . In this study, [email protected] is successfully prepared via an improved hydrothermal method combined with ion condensation. Then, we creatively adopt one-pot method, combining electrostatic adsorption with chemical crosslinking , to prepare lipase-nanocatalyst with excellent performance under mild conditions. [email protected] and lipase-nanocatalyst are characterized by FTIR, SEM, HRTEM , CLSM, CD, etc, the optimal conditions are explored in detail too. Lipase-nanocatalyst is 189 nm, and the loading ratio of free lipase is up to 67.6%. Compared with free lipase, specific activity is increased by 2.9 times, and it also broadens toleration to pH, thermal, organic solvents . In addition, lipase-nanocatalyst exhibits high storage stability and reusability . The residual activity is approximately 92.3% after the 10th recycle, and the cumulative catalytic activity is 13.4 times than that of free lipase. Finally, lipase-nanocatalyst is used to synthesize ethyl levulinate, with a production ratio of 68.6% for the first recycle, and the total output of EL is 12.9 times than that of free lipase after ten cycles. Thus, our findings provide a foundation for lipase-nanocatalyst showing several attractive features, such as easy preparation, excellent catalytic activity, good stability and reusability.
研究领域:
生物技术
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催化
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纳米技术
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酶学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Chun Chang,Shijie Wang,Pengkun Guo,Guizhuan Xu,Xiaoyang Zheng,Chaojun Du,Youzhou Jiao
Increasing efforts have been devoted to the production of bio-based chemicals from high solid content of renewable biomass to pursue optimal process efficiency and economics. In this study, the preparation of methyl levulinate (ML) by metal sulfate-catalyzed methanolysis from high solid content of cellulose was investigated. When the cellulose loading was 15%, 38.67% of ML yield can be obtained under the optimum reaction conditions. Al 2 (SO 4 ) 3 can be reused more than five times while maintaining high activity in the process. The characterization of cellulose particles confirmed that cellulose particles shrunk over the reaction time. The heterogeneous degradation kinetics of high solid content of cellulose in methanol could be explained by a shrinking core model. High solid loadings led to a decrease of the reaction rate constants of methanolysis. Using cellulose with a small particle size can improve the methanolysis reaction rate. The study also proposed comprehensive reaction pathways for ML production from high solid content of cellulose. To elucidate the methanolysis mechanism, an assessment of density functional theories for the calculation of glucose methanolysis at the molecular level is presented. All these results can inspire the development of ML synthesis technology through methanolysis from renewable biomass with high solid loadings.
研究领域:
生物化学
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可再生资源工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
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IF 9.446
Lingyun Jiang,Lipeng Zhou,Jinyu Chao,Huiting Zhao,Tianliang Lu,Yunlai Su,Xiaomei Yang,Jie Xu
Conversion of biomass derived carbohydrates to alkyl levulinates is an important process due to the wide application of alkyl levulinates as chemicals and biofuel additives. Efficient conversion of cheap and abundant glucose to alkyl levulinates over easily separated and regenerated solid catalyst is highly desirable. Here, the transformation of glucose to methyl levulinate (MLE) was studied over dual solid acid catalysts. The synergistic effect of solid Brønsted (B) acid and solid Lewis (L) acid was observed. A combined catalyst system consisting of both B acid and L acid was found to be more efficient for the production of MLE from glucose. 62% yield of MLE was given over the combined catalyst of SO 4 2− /ZrO 2 and Sn-Beta prepared by postsynthesis method at 170 °C for 24 h. The roles of L acid sites of SO 4 2− /ZrO 2 and Sn-Beta, and B acid sites of SO 4 2− /ZrO 2 were discussed in detail. Alternative biomass-derived carbohydrates also gave moderate to good yields of MLE. Recyclability studies indicated that the combined catalyst system can be reused without significant change in the yield of MLE, proving its easy recovery and thermal stability during regeneration.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2017
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IF 5.951
Xueyan Zhang,Yue Li,Lifang Xue,Shengtian Wang,Xiaohong Wang,Zijiang Jiang
A series of Lewis acid metals monosubstituted phosphotungstic acids HnPW11MO39 (HPWM, M = CuII, ZnII, CrIII, FeIII, SnIV, TiIV, and ZrIV; for Ti and Zr, the number of oxygen is 40) was evaluated in direct production of methyl levulinate (ML) from cellulosic biomass in a cascade reaction. One of the solid catalysts, H5PW11TiO40 (HPWTi), was found to be highly efficient for generation of ML from mono- or polysaccharides, reaching 51.3% ML yield directly from cellulose. And under microwave-assistance, the efficiency could be improved to a 62.6% ML yield within 2 h, which was almost the best result so far among reported solid catalysts. Identification of the reaction intermediates and the products provided some insight into the reaction mechanism and showed the requirement of certain Brønsted/Lewis acid ratio as 2.84/1 for HPWM. Moreover, the different metals in catalysts profoundly affected the Lewis or total acidity, and therefore, the catalytic activity and selectivity to ML or methyl glucosides (MG). HPWTi acted as a heterogeneous catalyst after being calcinated at 200 °C and showed high recyclability with minor loss of performance.
研究领域:
化学工程
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生物质能
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产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
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2022
·Vol. 48
·期 3
·1181-1198
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IF 3.134
Zhang Zhongze,Liu Zonghui,Gu Zhiyuan,Wen Zhe,Xue Bing
The catalytic transfer hydrogenation (CTH) reaction of ethyl levulinate (EL) with alcohol to γ-valerolactone (GVL) has been investigated over a series of Zr-based catalysts, including ZrO 2 , ZrP, Zrβ, ZrP/Hβ and ZrO 2 /HZSM-5. It is found that the simplest ZrO 2 was the most efficient for GVL production, giving an EL conversion as high as 97% and GVL selectivity of 91% after 7 h at 170 °C using 2-propanol as the hydrogen donor and solvent. The effects of reaction temperature, time and solvent on catalytic performance were investigated. Moreover, the kinetic behavior of CTH reaction of EL was also studied over ZrO 2 catalyst. The as-prepared ZrO 2 gives an Ea value of 32.9 kJ/mol, which is much lower than other catalysts in the literatures. Furthermore, those catalysts have been, respectively, characterized by XRD, IR, BET and NH 3 -TPD techniques to reveal the physical properties and structures of these materials. Correlating the catalyst performance with its physical and chemical properties uncovers that the higher pore diameter, lower total acidity and higher Lewis acid sites of catalyst surface would be the key to the catalyst performance. Graphical abstract
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DOI
高影响因子
RENEWABLE ENERGY
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2022
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IF 8.634
Lincai Peng,Xin Huangfu,Yao Liu,Huai Liu,Junhua Zhang
The processing of C6 sugars to alkyl levulinate (AL), a versatile biomass-derived building block, can be readily implemented via the straightforward acid-catalyzed reaction in alcohol medium while it remains a challenge to produce AL from C5 sugars in the one-pot procedure over a monolithic catalyst. In this contribution, a budget and multifunctional natural lignocellulose welded Zr–Al bimetallic hybrid (ZrAl@CS-MSA) has been successfully constructed with crude corn stalk as a sustainable support. The becoming Lewis and Brønsted acid sites of ZrAl@CS-MSA catalyst guarantee a high AL yield of 54.3% from xylose via a one-pot process in a renewable n -butanol medium. Experimental findings revealed that the sulfonic group of ZrAl@CS-MSA plays a significant role in the xylose dehydration, furfuryl alcohol etherification and alcoholysis reactions while Zr species is in charge of the transfer hydrogenation of furfural. The Al species enclosed in ZrAl@CS-MSA can regulate its Brønsted and Lewis acidity, accelerating the etherification and alcoholysis reactions as well as alleviating the over hydrogenation of AL. This work opens a green, sustainable and reliable avenue for producing C5 sugar-based AL using natural lignocellulose-related multifunctional catalysts.
研究领域:
催化化学
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生物质能
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绿色化学
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产品关联
DOI
高影响因子
Sustainable Energy & Fuels
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2022
·Vol. 6
·期 10
·2449-2461
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IF 6.813
Hongxing Wang,Yueqing Wang,Long Huang,Anying Geng,Fengjiao Yi,Yulei Zhu,Yongwang Li
Highly efficient synthesis of 1,4-pentanediol (1,4-PDO) from industrialized biomass-based products is still a challenge due to the inherent chemical stability of intermediate product γ-valerolactone. The aim of the present research was to evaluate the influence of the synthetic conditions of CuMgAl layered double hydroxides on their physicochemical properties as well as catalytic performance in pure ethyl levulinate hydrogenation to produce 1,4-PDO in fixed-bed reactors. Systematic characterization results demonstrated that the CuMgAl catalyst prepared with mixed alkali as the precipitant has appropriate amounts of acid-base sites and a higher electron cloud density of Cu, which could well activate the carbonyl functional groups in the substrate molecule, and thus excellent reaction performance can be obtained. Ultimately, two-stage-packed dual solid catalysts in fixed-bed reactors were designed for one-step conversion of industrial furfuryl alcohol (FOL) to 1,4-PDO through an alcoholysis hydrogenation integrated continuous process. 94.3% yield of 1,4-PDO can be obtained from FOL in this effective tandem reaction.
研究领域:
生物化学
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催化化学
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产品关联
DOI
高影响因子
ACS Catalysis
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2022
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IF 13.7
Yafei Li,Boyang Liu,Yu Wang,Shiqing Wang,Xiaocheng Lan,Tiefeng Wang
It is important but challenging to develop non-noble metal catalysts with high activity and selectivity for biomass conversion. The activation of C═O bond is a crucial step in biomass upgradation. Herein, a series of Ni-xP/Al2O3 catalysts with different P/Ni molar ratios were prepared for the conversion of ethyl levulinate to γ-valerolactone. The developed Ni-0.38P/Al2O3 catalyst was 5.4 times more active than conventional Ni/Al2O3 based on turnover frequency and significantly outperformed the state-of-the-art non-noble metal catalysts. The unique catalytic performance was ascribed to the formation of Ni3P phase, which was identified by several characterizations. The results of DFT calculation and characterization by XPS and CO-FTIR revealed that electron was transferred from Ni to P with the formation of Niδ+ sites. In situ FTIR for the surface reaction indicated that Niδ+ acted as a new active site to activate the C═O bond, which rendered the high intrinsic activity of Ni3P for the C═O hydrogenation of EL.
研究领域:
催化
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化学工程
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材料科学
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生物质能源
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2022
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IF 8.634
Yiwei Tang,Xiaoning Liu,Ran Xi,Le Liu,Xinhua Qi
As one of the important chemical feedstocks and biofuels, ethyl levulinate (EL) can be produced from biomass-derived furfural by consecutive hydrogenation, etherification and ring-opening reactions. However, this process normally requires two separate steps in different reaction systems, which is complex and energy consumption. Herein, Nb–Ni bifunctional ordered mesoporous carbons (Nb/ [email protected] ) were synthesized by a two-step process where [email protected] was firstly synthesized by a solvent evaporation induced self-assembly (EISA) process using F127 as a template agent, polyphenol gallic acid as carbon precursor and Ni 2+ as cross-linker, following with the supporting of Nb species in the [email protected] by an incipient wetness impregnation method. The as-synthesized Nb/ [email protected] samples were applied for the one-pot catalytic transformation of furfural to EL, and exhibited good activity with the highest EL yield of 83% under an optimized condition. Two possible pathways for the one-pot production of EL were proposed according to two intermediates: (1) hydrogenation of furfural to form furfuryl alcohol (FFA) that is then etherified with ethanol to form 2-(ethoxymethyl)furan (2-EMF); and (2) acetalization and etherification of furfural with ethanol to produce 2-(diethoxymethyl)furan (2-DMF). Then both 2-DMF and 2-EMF are converted to EL through acid catalyzed ring opening reaction. The dominant reaction pathway varied with the properties of the catalyst and the applied reaction conditions.
研究领域:
化学工程
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催化
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材料科学
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生物燃料
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2023
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IF 4.6
Fukun Li,Ronghe Yang,Ziting Du,Jinhang Dai,Xingmin Wang,Ning Li,Xianming Zhang,Yunqi Liu,Haifeng Gong,Zhenping Cai,Junjun Shi
Biochemicals and biofuel derived from biomass conversion have received much attention over past decades. Alkyl levulinates are considered as promising building block chemicals and green fuel additive. This work presents a facile and efficient catalytic strategy for one pot cascade conversion of furfural to alkyl levulinates over rare earth metal trifluoromethanesulfonates (RE(OTf) 3 ) in alcohol without external H 2 . Experimental results demonstrate that RE(OTf) 3 binds to the alcohol ((OTf) 3 -RE-O(H)R), possessing both Brønsted acid and Lewis acid, plays a key role for this cascade process. Meanwhile, the selectivity of alkyl levulinate is closely related to charge density of selected metal ion and the reduction potential of the selected alcohol. Among various tests, Lu(OTf) 3 , possessing the greatest charge density, exhibits the best catalytic activity in the lowest reduction potential of 2-propanol. 100% furfural conversion and 52.8% ispropanyl levulinate yield can be achieved at 190°C within 45 min. This catalyst can be recycled five times by direct vacuum distillation and regenerated by oxidative elimination of formed humins. Besides, a plausible reaction mechanism is also proposed.
研究领域:
化学工程
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生物化学
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产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 149
·期 10
·2749-2757
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IF 2.372
Lai Jinhua,Zhou Shuolin,Liu Xianxiang,Yang Yongjun,Lei Jing,Xu Qiong,Yin Dulin
Abstract The transformation of biomass-derived intermediates into value-added chemicals and liquid fuels is of great importance in sustainable chemistry. In this study, graphene oxide supported ZrO 2 (ZrO 2 /GO) was found to be an active heterogeneous catalyst for the transfer hydrogenation of ethyl levulinate to γ-valerolactone (GVL) with iso -propanol as the hydrogen donor. Several important reaction parameters such as the hydrogen donor, the reaction temperature and the catalyst loading were studied in detail with the aim to get a high yield of GVL. It was found that the structure of alcohols had a great effect towards the activity of the ZrO 2 /GO catalyst and the selectivity of GVL. Iso -propanol was the best hydrogen donor for the transfer hydrogenation of ethyl levulinate to GVL. The highest GVL yield reached 91.7% with an ethyl levulinate conversion of 96.2% under optimal reaction conditions. More importantly, the ZrO 2 /GO catalyst demonstrated a high stability without the loss of its catalytic activity during the recycling experiments, which should be due to the strong interaction between GO and ZrO 2 . Graphical Abstract The graphene oxide supported ZrO 2 (ZrO 2 /GO) catalyst showed high activity for the transfer hydrogenation of ethyl levulinate to GVL with a high yield up to 91.7%.
研究领域:
催化化学
·
可再生资源化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）