Reaction Kinetics Mechanisms and Catalysis
·
2018
·Vol. 125
·期 1
·71-84
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IF 1.515
Xie Yongdi,Wang Haijun,Liu Xiang,Xia Yongmei
Hydrogenation of levulinic acid and its esters to produce γ-valerolactone (GVL) is an important reaction in the process of biomass valorization. Herein, a series of novel and porous acid–base bifunctional Zirconium tripolyphosphate were successfully synthesized and utilized to catalyze the hydrogenation of ethyl levulinate (EL) to GVL. It was found that Zr-TPPA-3 with a large number of Lewis acid–base sites and a high specific area displayed the highest catalytic activity, a satisfied GVL yield of 93.1% with 99.5% EL conversion was obtained under the optimal reaction conditions. In addition, poisoning experiments revealed that the acid–base sites play a synergistic effect in the hydrogenation of EL to GVL, and finally proposed a plausible reaction mechanism.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
·
2018
·Vol. 65
·期 11
·1370-1378
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IF 0.862
Jianjia Wang,Ruiying Wang,Huimin Zi,Haijun Wang,Yongmei Xia,Xiang Liu
Catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) to γ-valerolactone (GVL) is an alluring reaction in the field of biomass catalytic conversion, but it normally depends on the consumption of H 2 . In this study, we report a porous Zr-containing inorganic pyrophosphate catalyst (ZrOPP), which was used as a catalyst for CTH of EL to GVL in the presence of isopropanol and characterized using FT-IR, py-FTIR, TGA, XRD, BET, XPS, ICP-AES, SEM, TEM, NH 3 -TPD, and CO 2 -TPD. We achieved a high yield of 94% GVL at 433 K for 11 hr. Furthermore, the ZrOPP has the trait of easy separation and could be reused more than five times without distinct decrease in activity and selectivity. In addition, this catalyst could also be applied to other catalytic hydrogenation reactions, such as those of cyclohexanone, acetophenone, 2-heptanone etc. Its outstanding performance was mainly ascribed to the acid sites from the Zr element and basic sites from phosphate groups interspersing on the surface of the catalyst.
研究领域:
化学工程
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生物质能转化
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Hao Chen,Houhang Ruan,Xilei Lu,Jie Fu,Timothy Langrish,Xiuyang Lu
In the present study, an economic and environmentally friendly bi-functional catalyst, Zr-SBA-15, has been prepared to develop a single-step process for synthesis of methyl levulinate (MLA) directly from furfural (FAL) in near-critical methanol without added H 2 . The presence of Zr in SBA-15, the structure of the Zr-SBA-15 catalyst, and its physical properties have been determined by X-ray diffraction (XRD), N 2 adsorption and desorption (N 2 -BET) and transmission electron microscopy (TEM). The Zr-SBA-15 catalyst has high activity for the production of MLA and good reusability. A possible reaction pathway containing two possible reaction pathways during this single-step synthesis of MLA has been proposed: the FAL has been transformed to β-Methoxy-2-furanethanol (MFE) and 2-Furfuryl methyl ether first, which then have been converted to MLA, and the conversion of FAL to MFE has been much easier and faster than that to 2-FME, which may be the major reaction pathway. The SBA-15 has given high activity for the conversion of FAL to MFE, and the incorporation of Zr has converted the MFE to MLA efficiently. The reaction of FAL to MFE to MLA has been found to be the dominant reaction. Finally, the catalyst has shown good reusability for at least five times without any reduction in the catalytic activity.
研究领域:
催化化学
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可再生化学
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产品关联
DOI
高影响因子
Journal of Cleaner Production
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2021
·
IF 9.297
Fengjiao Lai,Feng Yan,Pengju Wang,Fan Qu,Xuehua Shen,Zuotai Zhang
Efficient conversion of biomass-derived carbohydrates to alkyl levulinates is an important goal of biorefinery process, but is still challenging on applicable catalyst. Ce–Si pillared montmorillonite (CeSiM) clay heterostructures , incorporated with Wells-Dawson tungstophosphoric acid (H 6 P 2 W 18 O 64 , DPW), were prepared for the first time and used as the multifunctional catalyst for direct production of ethyl levulinate (EL) from various biomass-derived sugars. The DPW introduced by sol-gel method (DPW-CeSiM) has been effectively incorporated into the framework of porous CeSiM, while part of DPW was just absorbed on the surface of CeSiM by impregnation method (DPW-CeSiM-I). The DPW-CeSiM catalyst has large specific surface area owing to the insertion of Ce–Si pillars, and possesses strong Brønsted acidity and moderate Lewis acidity originated from the incorporated DPW and the Ce-doping, respectively. Due to the well synergistic effect of porous structure and dual acid, the DPW-CeSiM catalyst efficiently catalyzed the conversion of glucose into EL with 56.2% yield and nearly 100% conversion at 170 °C for 4 h. The recyclability studies certified that DPW-CeSiM catalyst showed higher stability than DPW-CeSiM-I over cycles and could be easily recovered from consecutive alcoholysis of biomass-derived sugars. The DPW-CeSiM catalyst also displayed high activity toward the conversion of other biomass-derived carbohydrates (fructose, sucrose, cellobiose and cellulose) into EL. Therefore, this work provides an instructive strategy for the design of efficient and stable DPW-based catalysts with dual acid sites uniformly distributed over the porous structure, which is obviously potential for industrial production of alkyl levulinates from carbohydrates and biomass.
研究领域:
化学工程
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生物质能
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2021
·
IF 6.064
Yafei Li,Xiaocheng Lan,Boyang Liu,Tiefeng Wang
A stable and highly efficient supported Cu-Ni catalysts for the conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) was developed. The catalysts were characterized by XRD, TEM, TPD, TPR, and XPS. The support effect of metal oxides (Al 2 O 3 , SiO 2 , ZrO 2 , and TiO 2 ) revealed that Cu-Ni supported on Al 2 O 3 showed the highest activity for EL hydrogenation to ethyl 4-hydroxypentanoate (EHP) and the subsequent intramolecular esterification of EHP to GVL. EHP intramolecular esterification to GVL in the ethanol solution was a reversible reaction with an equilibrium constant of 24 at 453 K. A simplified reaction kinetic network was established. The solvent had a significant influence on the reaction equilibrium and the catalyst stability. Cu-Ni/Al 2 O 3 in n-hexane solvent gave a higher GVL yield than that in ethanol solvent, and showed better recyclability than that in toluene solvent. With optimizing the conditions, Cu-Ni/Al 2 O 3 gave 99.9% conversion and 98% selectivity to GVL with a space–time yield of 1.13 g GVL g cat -1 h −1 in n-hexane solvent with good recyclability.
研究领域:
化学工程
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2022
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IF 9.224
Hengyu Hao,Yuya Abe,Haixin Guo,Xiao Zhang,Richard Lee Smith Jr
Bifunctional Lewis (L) acid (Ni- or Hf-) site–Brønsted (B) acid catalysts designed to promote transfer hydrogenation reactions were prepared via hydrothermal and solvothermal methods using safe mixed solvents and sustainable precursors. By using N,N-dimethylformamide as a basis for the desired basicity, mixed solvents could be identified that allowed catalysts to be prepared with tunable ratios of Lewis to Brønsted acid sites (L/B). The as-prepared catalysts promoted transfer hydrogenation of furfural and ethanolysis to form ethyl levulinate (EL) using ethanol as a solvent and hydrogen donor source. Among the catalysts, sulfonated Hf-catalysts prepared with a cyclopentanone/formic acid mixed solvent (Hf-CPN/FA) with an L/B ratio of 6.4 gave 95% furfural conversion with 51.9% yield of EL, while the sulfonated Hf catalyst prepared with a cyclopentanone/γ-valerolactone mixed solvent (Hf-CPN/GVL) with a total Lewis and Brønsted acid site amount of 85.1 μmol/g gave 100% furfuryl alcohol (FAL) conversion with 72.5% yield of EL. Brønsted acid sites promoted reversible acetalization of furfural with ethanol into 2-furaldehyde diethyl acetal, while Lewis acid sites promoted furfural transfer hydrogenation into FAL and EL and further conversion into γ-valerolactone. The methods developed in this work eliminate dipolar aprotic solvents and harsh acids used in catalyst synthesis and allow sustainable production of EL from biomass-related chemicals.
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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有机化学
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
·
IF 20.2
Jianfeng Shan,Zheng Chen,Dengfeng Wang,Guangyu Zhang,Sheng Li,Chuan Sun,Dongchao Wang,Caixia Ju,Xuelan Zhang,Lei Li
Catalytic conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) is a pivotal reaction in biomass conversion. Here, Pd/CoO x was studied and showed much higher EL hydrogenation reactivity than other Pd based catalysts. Further investigation revealed that EL conversion increased linearly with PdCo alloying degree elevating, indicating that PdCo alloy is ascribed to the superior reactivity of Pd/CoO x . Interestingly, Pd/CoO x with low Pd loading also exhibited excellent hydrogenation performance, and surface enrichment of Pd was identified as the main reason. Additionally, employing HZSM-5 as a co-catalyst not only accelerated ethyl 4-hydroxypentanoate lactonization, but also dramatically improved the stability of Pd/CoO x . As a result, a 99.1 % yield of GVL was achieved by the synergistic catalysis of HZSM-5 and Pd/CoO x containing 0.58 wt% Pd, which is comparable with the best catalyst ever reported in alkyl levulinate hydrogenation to GVL. Furthermore, the insights gained from this work have broad potential applications in biomass hydrogenation.
研究领域:
生物质能
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2021
·Vol. 23
·期 35
·19729-19739
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IF 3.676
Shijie Wang,Yihang Chen,Yu Jia,Guizhuan Xu,Chun Chang,Qianhui Guo,Hongge Tao,Caihong Zou,Kai Li
The fundamental understanding of glucose conversion to 5-ethoxymethylfurfural (EMF) and ethyl levulinate (EL) (value-added chemicals from biomass) in ethanol solution catalyzed by a Brønsted acid is limited at present. Consequently, here, the reaction pathways and mechanism of glucose conversion to EMF and EL catalyzed by a Brønsted acid were studied, using an experimental method and quantum chemical calculations at the B3LYP/6-31G(D) and B2PLYPD3/Def2TZVP level under a polarized continuum model (PCM-SMD). By further verification through GC/MS tests, the mechanism and reaction pathways of glucose conversion in ethanol solution catalyzed by a Brønsted acid were revealed, showing that glucose is catalyzed by proton and ethanol, and ethanol plays a bridging role in the process of proton transfer. There are three main reaction pathways: through glucose and ethyl glucoside (G/EG), through fructose, 5-hydroxymethylfurfural (HMF), levulinic acid (LA), and EL (G/F/H/L/EL), and through fructose, HMF, EMF, and EL (G/F/H/E/EL). The G/F/H/E/EL pathway with an energy barrier of 20.8 kcal mol−1 is considered as the thermodynamic and kinetics primary way, in which the reaction rate of this is highly related to the proton transfer in the isomerization of glucose to fructose. The intermediate HMF was formed from O5 via a ring-opening reaction and by the dehydration of fructose, and was further converted to the main product of EMF by etherification or by LA through hydrolysis. EMF and LA are both unstable, and can partially be transformed to EL. This study is beneficial for the insights aiding the understanding of the process and products controlling biomass conversion in ethanol solution.
研究领域:
生物化学
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催化化学
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理论化学
✓ 已验证
DOI
PubMed
高影响因子
Molecular Catalysis
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2024
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IF 3.9
Yesu Zhang,Yanhong Quan,Jun Ren
A series of sulfonated activated carbon catalysts (AC-SO 3 H- x ) were prepared by using sulfuric acid as the sulfating agent and used for the ethanolysis of furfuryl alcohol (FA) to ethyl levulinate (EL). The catalytic performance of AC-SO 3 H- x catalysts increased firstly and then decreased with introducing sulfuric acid and AC-SO 3 H-5 catalyst exhibited the highest activity with 95.3 % yield to EL and complete FA conversion, superior to that reported in the literature. Moreover, EL yield displayed the volcanic trend against with SO 3 H group concentration and the excellent catalytic performance of AC-SO 3 H-5 was attributed to appropriate surface acidity derived from the introduction of sulfonic acid groups (SO 3 H groups). Furthermore, it was firstly identified by the combination of FT-IR characterizations with Boehm's titration method that C-S bonds were formed through C atoms in phenolic hydroxyl groups of carbon surface bonding with SO 3 H groups. Additionally, the various sulfonation conditions and reaction conditions were optimized and it was found that low n FA /n EtOH (0.005) was very critical. This work provided a feasible strategy for the design of efficient carbon-based solid acid catalysts and innovatively elucidated the surface functional groups of carbon bonded to SO 3 H groups, which would drive the development of renewable FA to EL.
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Gang Wu,Shasha Liu,Jie Ren,Jiawei Zhu,Yun Yu,Suzana Yusup,Dengyu Chen,Shu Zhang,Yong Huang
The development of efficient and recyclable heterogeneous catalysts for the catalytic conversion of cellulose into high-value platform chemicals has garnered significant attention. Cobalt sulfide, recognized for its earth-abundance and recyclability, has emerged as a promising catalyst for the production of methyl levulinate (ML) from cellulose, albeit with a noted disparity in catalytic performance when compared to conventional homogeneous catalysts. In this study, various phosphorus-doped cobalt sulfides (CoS x P 2-x ) were employed to enhance the production of ML from cellulose, with a particular focus on the sulfide-phosphorus ratio. Notably, an optimal ML yield of 48.9 wt% and a complete conversion of cellulose were achieved at a sulfide-to-phosphorus ratio of 1:1. Comprehensive characterization of the synthesized CoS x P 2-x materials revealed that CoS 1.00 P 1.00 exhibited distinctive properties, such as the presence of ternary acid sites and the lowest Co 3+ /Co 2+ ratio among the series. Density functional theory (DFT) calculations elucidated that the bound electrons within the P-Co bonds were activated by the synergistic effects among Co, P, and S atoms, thereby diminishing the free energy barrier for the adsorption of reaction intermediates.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2022
·
IF 5.089
Fukun Li,Ronghe Yang,Ziting Du,Jinhang Dai,Xingmin Wang,Ning Li,Jie Zhang,Xianming Zhang,Yunqi Liu,Haifeng Gong,Hong Yin,Zhenping Cai
γ-Valerolactone (GVL) is considered as a versatile platform chemical obtained from biomass refinery. In this study, eco-friendly group III metal (Sc, Y, La) triflates were examined as homogeneous catalysts for microwave-assisted transfer hydrogenation of ethyl levulinate (EL) to GVL under mild conditions. Experimental results revealed that the selectivity of GVL has a positive relationship with the Lewis acidity of metal ion, which is related to effective charge density of the metal center (3.23, 2.81, 2.60 for Sc 3+ , Y 3+ , La 3+ , respectively). The stronger Lewis acidity of metal ion, the higher catalytic activity of MPV reduction. Among these catalysts, Sc(OTf) 3 exhibited the best catalytic activity, achieving 98.4% EL conversion and 92.4% GVL yield at 140 °C in 3.0 h. Furthermore, Sc(OTf) 3 showed high stability and recyclability for at least ten reaction cycles. In addition, a plausible reaction pathway and mechanism were proposed.
研究领域:
化学工程
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催化
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可再生能源
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绿色化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2023
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IF 12.9
Xugang Yang,Zaihao Yuan,Minghao Zhou,Feng Chen,Bo-Qing Xu,Hui Shi
Lewis acidic heterogeneous catalysts are known to be active for transfer hydrogenation of carbonyl compounds, which occur naturally or can be derived from renewable feedstocks. While previous studies have explored a myriad of Zr-based catalytic systems toward the Meerwein–Pondorf–Verley (MPV) reductions, few have determined intrinsic, site-specific rates under strict kinetic control across a sufficiently wide range of process conditions, causing misconceptions about the true potentials of these catalysts for the targeted transformations. Here, we present a quantitative assessment on the intrinsic activities of four types of Zr catalysts that are purportedly promising candidates for the MPV reductions; the selected catalysts contain active Zr sites within diversified local coordination and secondary solvating environments. A comprehensive kinetic study of ethyl levulinate (EL) MPV reduction in 2-butanol, combined with in situ quantitative titration of the active sites by selective poisoning with alkylphosphonic acid titrants of Lewis acid sites during the reaction, reveals dramatic differences in the relative fraction of active sites (13–78% of total Zr) and turnover rates (>300-fold) among the studied catalysts. Mechanistically, the hydride shift invariably remains as the sole rate-limiting step, regardless of the catalyst; the free energy barriers in both first-order and zero-order kinetic regimes and kinetic isotope effects, however, differ significantly among the catalysts. Through mechanism-based rate equations and transition-state-theory treatments, we further delineate that the wide variations in enthalpic and entropic components not only suggest disparate transition state structures and energetics but also reflect varying adsorption thermodynamics that are influenced by both reactant coordination at and solvent restructuring near the active sites.
研究领域:
催化
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化学动力学
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材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）