CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jingru Wang,Yingyong Wang,Xili Tong,Yunwei Wang,Guoqiang Jin,Xiangyun Guo
A 3 wt% Ir/SiC catalyst prepared by the wet impregnation method showed excellent catalytic activity and stability for the aqueous hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in a batch reactor system. LA was completely converted to GVL at 50 °C and 0.2 MPa of H 2 pressure with 100% selectivity and a high turnover frequency (TOF) of 333 h −1 . The high activity of Ir/SiC catalyst could be related to the Schottky-type contact between Ir and SiC solid phases, which promotes electron transfer between support and metal. Due to the excellent acid resistance of SiC support, the Ir/SiC catalyst showed high catalytic stability and nearly no loss of activity after 5 consecutive catalytic operation cycles.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Xi Xi,Sun Daolai,An Hualiang,Zhao Xinqiang,Wang Yanji
The self-condensation of levulinic acid was studied using cesium silicotungstate (Cs x H 4-x SiW 12 O 40 ) catalyst without solvent. The Cs x H 4-x SiW 12 O 40 catalyst was characterized by FT-IR, Raman, XRD, NH 3 -TPD, N 2 adsorption–desorption, SEM, and ICP. The results showed that the structure of Keggin was well retained in all samples of Cs x H 4-x SiW 12 O 40 catalyst. With a decrease of Cs content, the acid strength of Cs x H 4-x SiW 12 O 40 catalyst decreased, and thus the yield of cyclic C 10 products decreased accordingly, while that of linear C 10 products increased. The effect of reaction conditions on levulinic acid self-condensation was studied using Cs 2.5 H 1.5 SiW 12 O 40 (H 2 SO 4 ) catalyst. Under the conditions of catalyst amount of 15 wt.%, reaction temperature of 130 °C, and reaction time of 6 h, the conversion of levulinic acid was 53.8%, and the total selectivity of C 10 products were 83.1%. Through spectroscopic characterization and DFT calculation, the possible structures of C 10 products of levulinic acid aldol self-condensation were deduced. The results showed that levulinic acid condensed in two different paths to form two intermediates, 4-hydroxy-4-methyl-6-oxononanedioic acid and 3-acetyl-4-hydroxy-4-methylheptanedioic acid. The two intermediates were then subjected, respectively, to lactonization and intramolecular dehydration to three cyclic C 10 products: 5-(2-methyl-5-oxotetrahydrofuran-2-yl)-4-oxopentanoic acid, 3-(2-methyl-5-oxotetrahydrofuran-2-yl)-4-oxopentanoic acid, and 3-(3-acetyl-2-methyl-5-oxotetrahydrofuran-2-yl) propanoic acid, and to obtain the linear C 10 product, (E)-4-methyl-6-oxonon-4-enedioic acid.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2014
·
IF 3.916
Huifang Ren,Buana Girisuta,Yonggui Zhou,Li Liu
Cellulose depolymerization to levulinic acid (LA) was catalyzed by acidic ionic liquids (ILs) selectively and recyclably under hydrothermal conditions. The effects of reaction temperature, time, water amount and cellulose intake were investigated. Dilution effect becomes more pronounced at lower cellulose intake, dramatically improving the yield of LA to 86.1%. A kinetic model has been developed based on experimental data, whereby a good fit was obtained and kinetic parameters were derived. The relationships between IL structure, polymeric structure and depolymerization efficiency were established, shedding light on the in-depth catalytic mechanism of IL, inclusive of acidity and hydrogen bonding ability. The LA product can be readily separated through extraction by methyl isobutyl ketone (MIBK) and IL can be reused over five cycles without loss of activity. This environmentally friendly methodology can be applied to selective production of LA from versatile biomass feedstocks, including cellulose and derivatives, glucose, fructose and HMF.
研究领域:
生物化学
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Mei Xiang,Jingna Liu,Wenqian Fu,Tiandi Tang,Dongfang Wu
A hierarchically porous ETS-10-supported highly dispersed Ni catalyst was designed to selectively catalyze the conversion of cellulose to levulinic acid under mild reaction conditions. Full conversion of cellulose and remarkably high yield (91.0%) of levulinic acid are achieved due to the synergistic effect of the unique porous structures and Lewis acid sites in the presence of a hydrogen atmosphere. Moderate Lewis acidic centers of the heterogeneous catalyst are revealed to play a positive role in activating the reaction substrates and intermediates, resulting in prominently catalytic activity. Meanwhile, hierarchical pores centered at 16 nm in ETS-10 benefit the mass transfer and therefore further enhance its catalytic performance. Also, during the process of levulinic acid formation, introduction of hydrogen is responsible for converting cellulose thoroughly and keeping the metal Ni from oxidization by the oxy-compounds, which is distinctive from the widely reported pathway dominated only by cellulose hydrolysis.
研究领域:
催化
·
化学工程
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Zuojun Wei,Qing Li,Yuran Cheng,Mei Dong,Zuyi Zhang,Xinmiao Zhu,Yingxin Liu,Yong Sun
CoRe bimetallic catalysts with low loading were designed for hydrodeoxygenation of levulinic acid to γ-valerolactone. Results show that the 1 wt % Co0.5Re0.5/TiO2 catalyst achieved the highest yield of γ-valerolactone (>99%) at 220 °C, 3 h, a 1,4-dioxane solvent and Co/levulinic acid molar ratio of 1:1760, with a turnover frequency (TOF) of 1328 h–1. The catalyst can be reused four times with only slight activity loss. The catalyst was characterized with various physicochemical measurements, and its adsorption styles with H2 and levulinic acid were calculated by density functional theory. The results reveal that four main factors are related to its excellent catalytic performance. First, the Re oxides synergize with Co by spillover of the dissociated H atoms, which increases the apparent dispersion of Co and promotes the reaction. Second, the low loading of 1 wt % allowed the metal nanoparticles to be well dispersed with a very fine size of ca. 1.24 nm, which may expose more active sites to the substrate and result in a higher catalytic efficiency. Third, CoRe formed an amorphous alloy with the formula Co-ReO1.6, which showed a synergistic effect during the reaction. Finally, the TiO2 support was nonporous and hydrophilic, which would be beneficial for the mass diffusion of the reaction components to be adsorbed/desorbed onto the vicinity of the metallic active sites and lead to a high TOF in the hydrodeoxygenation process.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Yu Nanxi,Lu Houfang,Yang Wei,Zheng Yuxin,Hu Qiang,Liu Yingying,Wu Kejing,Liang Bin
In the process of converting biomass into high value-added chemicals, transfer hydrogenation as a mild hydrogenation method has attracted more and more attention. The catalysts with hydrogenation sites (nano CuNi alloy) and acid sites (Al oxide) highly dispersed on the surface of a stable support (active carbon) were prepared and the importance of acid sites for the activity of CuNi catalysts in transfer hydrogenation was demonstrated. The catalysts showed promising catalytic activity on the transfer hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL). The CuNi-1Al/AC with 5 wt.% CuNi alloy and 5 wt.% Al got 97.2% GVL yield and 100% LA conversion at 220 ℃ in isopropanol for 2 h. The high activity of the catalyst is attributed to the promoted esterification by the supported acid sites. The Al-modified catalyst also showed activity for esterification reaction in different alcohol hydrogen donors. The catalyst occurs inactive during the cycle due to the shedding of the active components, and the stability of catalyst is effectively improved by a stepwise impregnation. Graphical abstract
研究领域:
催化化学
·
可再生资源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Junbo Liu,Shengyang Tao
Electrocatalysis of biomass-derived platform molecules is an effective way to utilize biomass. Electrodes for the electrocatalytic hydrogenation of levulinic acid (LA) to selectively produce valeric acid (VA) have been extensively studied. Improving the electrocatalytic activity of electrodes for LA conversion is a meaningful and challenging task. This paper prepared β-PbO/Pb electrodes by laser processing. The higher adsorption of LA on the β-PbO surface was confirmed by in situ infrared and Raman spectra and density functional theory (DFT) calculations. The β-PbO/Pb electrode exhibited higher electrocatalytic activity than the α-PbO/Pb and Pb electrodes. Complete conversion of LA was achieved at a much lower electrode potential of −1.4 V (vs RHE) with an 85 % yield of VA and greater than 90 % selectivity. In addition, laser processing technology provides a strategy for the rapid processing of electrodes to enable large-scale continuous production in industry.
研究领域:
化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Licheng Song,Shigao Shen,Lexuan Zhao,Zhen Song,Zhiwen Qi,Hongye Cheng
Deterpenation of lemon essential oil is essential for improving product quality and enriching bioactive compounds but challenging due to the weak selectivity caused by mildly polar compounds like citral and limonene. In this work, an efficient extractive deterpenation process was developed using a levulinic acid (LEA)-based natural eutectic solvent (NAES). Water was identified as the optimal natural hydrogen bond acceptor, with its content modulating the strength of hydrogen bonding between NAES and the target solute citral. A 2 wt% water content was employed for citral extraction, while higher water content aided citral recovery. Furthermore, hexane was selected as the anti-extractant from 2508 solvents to enhance selectivity and reduce limonene co-extraction. After sequential extraction and back-extraction with water and hexane, followed by vacuum distillation, high-purity citral (96.2 wt%) was obtained. The hydrous LEA NAES was recovered and reused effectively. This work presents an efficient and recyclable strategy for the extractive deterpenation of lemon essential oil using NAES.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Zicheng Du,Jiao Li,Yi Xie,Baojie Liu,Wenxuan Mo,Chengrong Qin,Chen Liang,Caoxing Huang,Shuangquan Yao
Directed hydrolysis of hemicellulose to produce high-purity derivative sugars offers a green and value-added utilization pathway. This study investigates the catalytic hydrolysis kinetics of hemicellulose using levulinic acid (Lev), focusing on the effects of temperature, reaction time, and acid concentration on the distribution of target products (xylose, arabinose) and inhibitory by-products (furfural, acetic acid). Under optimized conditions, xylose and arabinose concentrations reached 8.02 and 0.86 g/L. A two-phase kinetic model reveals that reaction temperature optimization enhances monosaccharides selectivity and limits by-product accumulation. Incorporating the pKa of Lev into the kinetic rate constant improves model accuracy across varying acid concentrations. In the Lev system, the activation energy for xylose degradation (87.06 kJ·mol −1 ) exceeds that of the hydrolysis (51.28 kJ·mol −1 in the fast stage and 78.31 kJ·mol −1 in the slow stage), a trend opposite to that observed with inorganic acids, indicating enhanced selectivity for monosaccharide production. Density functional theory analysis reveals that the carboxyl group in Lev facilitates glycosidic bond cleavage through hydrogen bonding at the molecular level. Thermodynamic analysis shows that hemicellulose hydrolysis is an endothermic, non-spontaneous process driven by temperature, with a more favorable energy profile for xylose formation than degradation, which helps to achieve the effective accumulation of monosaccharides. These findings reveal the catalytic role of Lev in hemicellulose hydrolysis and support its application in the efficient and sustainable production of value-added sugars.
研究领域:
生物能源
·
绿色化学
·
碳水化合物化学
·
反应动力学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 71
·40989-40995
·
IF 2.936
Ruifeng Wang,Lungang Chen,Xinghua Zhang,Qi Zhang,Yuping Li,Chenguang Wang,Longlong Ma
Novel catalytic material with high catalytic activity and hydrothermal stability plays a key role in the efficient conversion of levulinic acid (LA) to γ-valerolactone (GVL) in water. In this study, mixed oxides Al2O3–TiO2, Al2O3–MoO3 and Al2O3–Co3O4 were synthesized by co-precipitation using aqueous solution of NaOH as precipitant. Ru catalysts supported on mixed oxides were prepared by impregnation method and their catalytic performances were tested in the hydrogenation of LA to GVL on a fixed bed reactor. The physicochemical properties of the catalysts were characterized by XRD, H2-TPR, NH3-TPD, and BET techniques. The TiO2 component significantly affected the acidity of the catalyst, and thus its catalytic activity for the GVL yield was affected. The desired product GVL with a yield of about 97% was obtained over the Ru/Al2O3–TiO2 catalyst under mild conditions (WHSV = 1.8 h−1, T = 80 °C). Moreover, the catalyst Ru/Al2O3–TiO2 exhibited excellent thermal stability in the test period of time.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2013
·
IF 2.853
Fan Yang,Jie Fu,Jing Mo,Xiuyang Lu
The mixed-acid systems of four Lewis acids (FeCl3, CrCl3, ZnCl2, and CuCl2) combining three Brønsted acids (H2SO4, HCl, and H3PO4) were evaluated for the decomposition of glucose to produce levulinic acid (LA). The CrCl3–H3PO4 system had a strong synergic catalytic activity for the decomposition of glucose to LA. The effects of the ratio of CrCl3 and H3PO4 on glucose, fructose, and 5-hydroxymethylfurfural (5-HMF) decompositions were investigated. The mixed-acid system showed the strongest synergic catalytic activity for glucose, fructose, and 5-HMF decompositions when the ratio of CrCl3 in the CrCl3–H3PO4 system was 0.4–0.5. To probe the synergic catalysis mechanism of the CrCl3–H3PO4 system, the synergic catalytic activities of CrCl3–phosphates (KH2PO4, K2HPO4, and K3PO4) systems on glucose decomposition were also evaluated. The possible synergic catalysis mechanisms were proposed. This study provides insights for the synergic catalysis mechanism of hexose conversion to yield LA.
研究领域:
化学工程
·
可再生能源
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Shengbin Shi,Yuanfeng Wu,Mengting Zhang,Zongqi Zhang,Olayinka Oderinde,Lijing Gao,Guomin Xiao
The conversion of cellulose to levulinic acid (LA) and other platform chemicals is a promising route to solve the energy crisis. For this purpose, a series of new SO 3 H-functionalized ionic liquids (ILs), containing different halogen-anions were synthesized and applied for catalytic conversion of cellulose to LA. The structure, thermal stability, and acidity of SO 3 H-functionalized ILs were characterized by Nuclear magnetic resonance (NMR) spectra, Fourier-transform infrared (FT-IR), High resolution mass spectrometry (HRMS), thermogravimetric analysis (TGA), and Hammet acidity method. The results revealed that as the size of halogen anions increased, the Hammett acidity gradually increased from SO 3 H-functionalized ILs containing fluorine- to chlorine- and then to bromine-anions. When SO 3 H-functionalized ILs were used as a catalyst for the production of LA from cellulose, the yield of LA gradually increased as the size of halogen-anions increased from fluorine- to chlorine- and then to bromine-anions. Among the SO 3 H-functionalized ILs, 1,1-bis(3-(4-sulfobutyl)imidazolium-1-yl)butylene bromine ([BSim]Br) exhibited the best catalytic activity with 76.5% yield of LA in cellulose/[BSim]Br/H 2 O ( m / m / m = 1:9:8) reaction system at 180 °C for 20 min, which was the highest yield compared to previous literature reports using ILs as catalyst. Besides, the [BSim]Br was easily recovered and showed high catalytic activity after five cycles. The efficient catalyst, [BSim]Br is then proposed to have a great potential for mass production of LA from biomass.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）