FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Qingpo Peng,Xiuge Zhao,Difan Li,Manyu Chen,Xinjia Wei,Jian Fang,Kai Cui,Yuan Ma,Zhenshan Hou
The heterogeneous heteropolyacid-catalyzed acetalization of glycerol with acetone was investigated under solvent-free conditions. In this work, the calcined Ta/W mixed addenda heteropolyacid catalyst ({H 20 }-355) was employed as a solid acid catalyst and showed much higher activity than these soluble Keggin-type catalysts in the acetalization of glycerol with acetone due to its superacidity ( H 0 = −12.95). Meanwhile, it showed high stability in catalytic recycles and extended for acetalization of glycerol with the other aldehydes and ketones . Based on the catalyst characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), 31 P NMR spectra, FT-IR spectra, pyridine-absorbed FT-IR, and Hammett acidity functions ( H 0 ) by UV–vis spectroscopy, it was found that the acidic strength of the Ta/W mixed addenda heteropolyacid was highly dependent on the contents of crystalline water that could be tuned by calcination temperature. Notably, the solid superacid catalyst {H 20 }-355 was swollen by acetone, exhibiting an interesting “pseudo-liquid” behavior, which served as a microreactor and facilitated the reaction. Furthermore, after the acetalization reaction of glycerol with furfural (98% yield of acetal) on {H 20 }-355 catalyst, the furan ring of the acetal products can be hydrogenated sequentially into dioxolane or dioxane with Pd/C catalyst under room temperature condition without the need of any isolation procedure.
研究领域:
化学工程
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催化科学
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可再生燃料合成
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 6
·2362
·
IF 3.4
Kuntong Song,Yi Li,Ruiqi Zhang,Nan Wang,Junhong Liu,Wenxia Hou,Qing Zhou,Xingmei Lu
Compared with conventional pyrolysis, steam-assisted pyrolysis of polyethylene terephthalate (PET) can effectively eliminate char and upgrade terephthalic acid (TPA). However, during steam-assisted pyrolysis of PET, the degree of cracking still varies greatly, and while some of the product is excessively cracked to gas, the other part is still insufficiently cracked. In addition, these two types of products seriously affect the yield and purity of TPA. To further enhance the TPA, an attempt was made to reduce these impurities simultaneously by synergistic catalysis among the different components of the metal–acid catalyst. Through a series of experiments, Pt@Hzsm-5 was screened as the optimal catalyst. In the catalytic steam-assisted pyrolysis of PET, the optimum reaction temperature decreased to 400 °C, the calculated yield of TPA increased to 98.23 wt%, and the purity increased to 92.2%. The Pt@Hzsm-5 could be recycled three times with no significant decrease in the obtained yield of TPA. The catalytic mechanism of the Pt@Hzsm-5 was investigated through the analysis of the products and isotope tracing experiments. The Pt catalyzed the hydrogen transfer reaction between the water molecules and PET molecules, which inhibited the excessive cracking of TPA by improving the hydrogen transfer efficiency, reduced the generation of gaseous products, and improved the calculated yield of TPA. In contrast, the Hzsm-5 catalyzed the reaction of monovinyl ester cracking to TPA, effectively reducing the impurities in the solid product, increasing the olefin yield, and improving the purity of TPA. This discovery not only clarifies the synergistic catalytic effect of the Pt@Hzsm-5 in the steam-assisted pyrolysis of the PET reaction but also lays the foundation for further screening of other inexpensive metal–acid catalysts. This is of great significance to realize the industrial application of TPA preparation by PET pyrolysis.Keywords:PET;metal–acid catalyst;steam-assisted pyrolysis;TPA
研究领域:
化学工程
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催化材料
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产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2021
·Vol. 2021
·期 29
·3013-3018
·
IF 2.524
Yi Wang,Jialu Shen,Yu Huang,Xiang Liu,Qiuxia Zhao,Didier Astruc
Graphical Metal-free H 2 or D 2 evolution is obtained in a few minutes from acid- or base-catalyzed hydrolysis of diboronic acid, respectively, under ambient conditions and is coupled to hydrogenation reactions. Kinetic studies allow proposing mechanisms by considering primary kinetic isotope effects observed for both acid- and based-catalyzed reactions with D 2 O. The efficient production of H 2 from hydrogen-rich sources, particularly from water, is a crucial task and a great challenge, both as a sustainable energy source and on the laboratory scale for hydrogenation reactions. Herein, a facile and effective synthesis of H 2 and D 2 from only acid- or base-catalyzed metal-free hydrolysis of B 2 (OH) 4 , a current borylation reagent, has been developed without any transition metal or ligand. Acid-catalyzed H 2 evolution was completed in 4 min, whereas the base-catalyzed process needed 6 min. The large kinetic isotopic effects for this reaction with D 2 O, deuteration experiments and mechanistic studies have confirmed that both H atoms of H 2 originate from water using either of these reactions. This new, metal-free catalytic system holds several advantages, such as high efficiency, simplicity of operation, sustainability, economy, and potential further use.
研究领域:
化学
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能源科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
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IF 2.843
Weiting Ma,Yufeng Hu,Jianguang Qi,Lihu Wei,Xianming Zhang,Zhenyu Yang,Siqi Jiang
The effects of solvent, acid specificity, acid concentration, added salt, and reaction temperature on the yields of trioxane and formic acid (byproduct) in paraformaldehyde + acid (or acid + salt) + aprotic solvent were investigated. The mechanism that underlies the yield of paraformaldehyde and the selectivity of trioxane was determined. A highly practical and efficient synthesis of trioxane by a salt-mediated and acid-catalyzed yield of paraformaldehyde in sulfolane media was developed. The method increased the yield of paraformaldehyde by more than 5 times and decreased the formic acid concentration by 10 times compared to the commercial synthesis of trioxane in an aqueous reaction system (formaldehyde + H2SO4 + H2O).
研究领域:
有机化学
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工业化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Hao Xu,Shanshan Xiong,Yuan Zhao,Lingjun Zhu,Shurong Wang
Furfural is an important platform chemical that can be produced by dehydration of pentose, which is an important building block of lignocellulosic biomass. In this study, xylose was chosen as the reaction substrate, and a carbon-based solid acid prepared from pectin was used as the catalyst in a mixed solvent consisting of water and γ-valerolactone (GVL). FTIR results showed that the sulfonated catalyst had typical characteristic peaks of sulfonic groups, while the results based on NH3-TPD and elemental analysis showed that the sulfonation temperature changed the surface acid concentration and acid site intensity of the catalyst. A furfural yield of 80.4% and a xylose conversion of 100% were obtained at 170 °C for 60 min. The conversions and product yields were influenced by the reaction temperature, reaction time, solvent composition, and catalyst acidity. Different sulfonation temperatures can change the acidity of the catalyst, which determines the catalytic performance of the catalyst.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2019
·
IF 4.191
Xiaoyun Li,Jiaxin Yang,Rui Xu,Lefu Lu,Fangong Kong,Min Liang,Lijie Jiang,Shuangxi Nie,Chuanling Si
The production of platform chemicals from lignocellulosic biomass is scientifically valuable but technologically challenging. With the aim to establish a green reaction system for the production of furfural from lignocellulosic biomass, in the current work, H-SAPO-34 was investigated for catalysis of the conversion of Eucalyptus sawdust to furfural in γ-valerolactone (GVL). H-SAPO-34 was prepared and characterized by XRD, SEM, FTIR, BET, TGA and ammonia adsorbed FTIR. H-SAPO-34 possesses Brønsted and Lewis acid sites and a large specific surface area. The average pore diameter of H-SAPO-34 was 0.86 nm, which is beneficial for the spread of xylose and furfural and the inhibition of humin production. In this work, a peak furfural yield of 99.28% from Eucalyptus was achieved at 210 °C in 120 min with 30 g/L H-SAPO-34. The Brønsted/Lewis acid bifunctionality and the solvent effect of γ-valerolactone possibly contributed to the high furfural yield from real biomass. The kinetics of the conversion of Eucalyptus sawdust to furfural was also studied, and the activation energy for furfural production was calculated. Additionally, the catalytic activity and stability of the regenerated catalyst were estimated.
研究领域:
化学工程
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可再生资源与环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Bin Hu,Qiang Lu,Yu-ting Wu,Wen-luan Xie,Min-shu Cui,Ji Liu,Chang-qing Dong,Yong-ping Yang
The catalytic fast pyrolysis of cellulose impregnated with phosphoric acid (H 3 PO 4 ) offers a promising method for the selective production of levoglucosenone (LGO), a valuable anhydrosugar product. However, the fundamental mechanism for selective LGO formation is unclear. Herein, quantum chemistry calculations and catalytic fast pyrolysis experiments were performed to reveal the formation mechanism of LGO in H 3 PO 4 -catalyzed cellulose pyrolysis. H 3 PO 4 significantly decreased the energy barriers of the pyrolytic reactions and altered the competitiveness of the LGO formation pathways, promoting LGO formation. Through different pathways in the non-catalytic and H 3 PO 4 -catalyzed conditions, LGO is mainly produced from the primary decomposition of glucose units of cellulose and secondary conversion of levoglucosan. The major catalytic formation pathways of LGO comprise similar reactions, with dehydration at the 3-OH + 2-H site as the rate-determining step. Importantly, secondary conversion of 1,4;3,6-dianhydro-α- d -glucopyranose is not feasible for LGO formation, in contrast to previous reports. In addition, a high degree of polymerization is beneficial for the selectivity of LGO formation in the catalytic process, because the glycosidic bond is important for the formation of the bicyclic structure (1,5- and 1,6-acetal rings).
研究领域:
化学工程
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生物质能
·
量子化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Liangkun Hou,Yingying Liu,Kejing Wu,Yingming Zhu,Houfang Lu,Bin Liang
The acid-catalyzed desorption of the MDEA CO2-rich liquid under the electrochemical reaction can lower the desorption temperature, thereby reducing the energy consumption for regeneration. In this work, disodium 4,5-dihydroxy-1,3-benzenedisulfonate (tiron) was used as an acidic medium for the electrocatalytic regeneration of the MDEA CO2-rich solution. The results show that the CO2 desorption efficiency reaches more than 90% at 25 °C for the 0.3 M MDEA (0.1 M tiron) system. At 50 °C, compared with 3 M MDEA (without tiron), the maximum CO2 desorption rate and desorption efficiency of the 3 M MDEA (with 0.1 M tiron) CO2-rich solution increased by 27.4 and 18.3%, respectively. Elevating the temperature can increase the quantity of CO2 desorption and the degree of MDEAH+ deprotonation as well as the reactivity of tiron on the electrode, so the desorption rate of CO2 can be further improved by the oxidation of tiron releasing H+ in coordination with thermal desorption.
研究领域:
化学工程
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环境科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Yuying Zhang,Chuang Li,Zhongtian Du,Xiao Chen,Changhai Liang
Transformation of renewable biomass into chemicals has attracted much attention recently. Efficient catalytic dehydration of biomass-derived sorbitol into isosorbide over solid acid catalysts under moderate reaction conditions is still a technical challenge. A series of silver-exchanged phosphotungstic acid catalysts were prepared by an ion-exchanged process, and dehydration of sorbitol into isosorbide was performed under solvent-free conditions. More than 99% conversion of sorbitol was obtained with 83% selectivity of isosorbide over Ag 1 H 2 PW catalyst at 140 °C within 1 h, which are comparable with that using a homogeneous phosphotungstic acid (HPW) catalyst. The silver-exchanged phosphotungstic acid catalysts were characterized by various techniques such as XRD, FT-IR, Raman, NH 3 -TPD and Py-IR to build a relationship between the catalytic activity and their natures. Ag 1 H 2 PW exhibited much higher activity for catalytic dehydration of sorbitol to isosorbide compared with Ag 2 H 1 PW and Ag 3 PW under the same reaction conditions, which was attributed to the stronger acidity and higher amount of Brönsted acid sites. Moreover, Ag 1 H 2 PW could be easily regenerated by 65% HNO 3 solutions and used repeatedly at least 3 times without obvious loss of catalytic activity.
研究领域:
化学工程
·
催化
·
可再生能源
✓ 已验证
产品关联
DOI
ChemistrySelect
·
2024
·Vol. 9
·期 40
·e202402030
·
IF 1.9
Wei Tang,Haojie Qian,Xinyue Wang,Caoxing Huang
Graphical The solid acid catalysts were triumphantly prepared using the residues of poplar sawdust's enzymatic hydrolysis, which displayed the most acidic sites and high catalytic activity, and achieved the highest furfural yield and furfural selectivity during xylose conversion. The utilization of biomass as a carbon source for the synthesis of renewable solid acid catalysts (SA) has emerged as a prominent research direction in the field of heterogeneous catalysis. Based on the challenges associated with reusing residues from lignocellulosic biorefining, the biomass-based SA (BCSA) were prepared using poplar sawdust (PS), hydrothermally pretreated PS (PPS), and the residue of PPS's enzymatic hydrolysis (ER). The characterization revealed that all three types of BCSA were loaded with catalytic groups, and the BCSA synthesized using ER rich in lignin components exhibited a highly efficient catalytic structure. Furthermore, the catalysis of a 20 g/L xylose solution with BCSA-ER as SA also achieved the highest furfural yield (89.3%) and furfural selectivity (90.3%). The findings of this study suggested that lignin holds significant potential as a carbon carrier for SA, thereby offering a viable solution for utilizing by-products from lignocellulosic biorefining.
研究领域:
生物化学
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2014
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IF 5.039
Huiling Li,Aojie Deng,Junli Ren,Changyu Liu,Qi Lu,Linjie Zhong,Feng Peng,Runcang Sun
Selectively catalytic hydrothermal pretreatment of corncob into xylose and furfural has been developed in this work using solid acid catalyst ( SO 4 2 - /TiO 2 –ZrO 2 /La 3+ ). The effects of corncob-to-water ratio, reaction temperature and residence time on the performance of catalytic hydrothermal pretreatment were investigated. Results showed that the solid residues contained mainly lignin and cellulose, which was indicative of the efficient removal of hemicelluloses from corncob by hydrothermal method. The prepared catalyst with high thermal stability and strong acid sites originated from the acid functional groups was confirmed to contribute to the hydrolysis of polysaccharides into monosaccharides followed by dehydration into furfural. Highest furfural yield (6.18 g/100 g) could be obtained at 180 °C for 120 min with 6.80 g/100 g xylose yield when the corncob/water ratio of was 10:100. Therefore, selectively catalytic hydrothermal pretreatment of lignocellulosic biomass into important platform chemicals by solid acids is considered to be a potential treatment for biodiesel and chemical production.
研究领域:
生物化学
·
可再生资源与环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 11
·5312-5320
·
IF 3.925
Keping Wang,Mei Wu,Yixuan Liu,Ying Yang,Hu Li
Five-membered nitrogen heterocyclic pyrroles have extremely high physiological activity and are widely used in medicine, agriculture, materials chemistry, industry, and supramolecular chemistry. Developing a mild and eco-friendly way to synthesize functionalized pyrroles from biologically derived materials is desirable. In this study, biomass-derived 2,5-dimethylfuran can react with a series of aromatic amines to synthesize 2,5-dimethyl-N-arylpyrroles through acid-enabled ring-opening and Paal–Knorr condensation in one pot. Among the tested acid catalytic materials, a new magnetic biocarbon-based sulfonic acid solid catalyst (WK-SO3H) showed excellent catalytic performance in the synthesis of N-substituted pyrroles (up to ca. 90% yield) and was easy to separate and recover by an external magnetic field. The ring-opening of furan proved to be the rate-determining step of the above one-pot multi-step conversion process, and 2,5-hexanedione is a key intermediate for the cascade reaction, while the addition of water could significantly enhance the above-mentioned ring-opening reaction. Furthermore, multiple characterization methods (e.g., FT-IR, TGA, XRD, NH3-TPD, and XPS) confirmed that WK-SO3H has good stability in the aqueous reaction system.
研究领域:
有机化学
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生物化学
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材料科学
✓ 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）