APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yakai Chen,Xinya Feng,Xiaohan Yu,Xingliang Xu,Jing Xu
Catalytic aldol condensation of biomass-derived furfural (FAL) with acetone (AC) into the single-condensation product 4-(2-furyl)-3-buten-2-one (FAC) is a potential and promising strategy for biomass improvement process and still challenging. Metal oxides exposed different crystal facets can regulate their surface structure and adsorption activation ability, which can provide an opportunity to enhance aldol condensation performance. Here, nanoparticles-CeO 2 (P-CeO 2 ), nanorods-CeO 2 (R-CeO 2 ) and nanocubes-CeO 2 (C-CeO 2 ) with (111), (110) and (100) plane predominant exposure was prepared to explore their catalytic performance for the aldol condensation of FAL with AC to obtain FAC. The serial detailed characterizations, experimental results and density functional theory calculation revealed that R-CeO 2 with a dominant (110) facet possesses appropriate surface adsorption energy, abundant oxygen vacancy (Ov) and excellent acid-base properties, which can effectively boost the adsorption and activation of FAL and AC and reduce the barrier of aldol condensation reaction based on the acid-base catalysis mechanism. The work would reveal the influence of CeO 2 crystal facet on the aldol condensation and provide a broad potential for the rational design of metal oxide catalysts for other acid-base catalytic reactions.
研究领域:
催化化学
·
生物质能
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 3
·521
·
IF 3.426
Lei Han,Haifeng Cai,Xu Chen,Cheng Zheng,Weihong Guo
Ultra-high molecular weight polyethylene (UHMWPE)/epoxy composites with excellent adhesive properties were prepared by forming an interface membrane on the UHMWPE fiber surface. The interface membrane of the UHMWPE fiber and epoxy resin was polymerized by an aldol condensation between polyvinyl alcohol (PVA) and glutaraldehyde. Different surface treatment methods of UHMWPE fibers were optimized and the two-step PVA-glutaraldehyde condensation (Corona-PG-2S) method is the best. The interfacial adhesion between UHMWPE fiber and epoxy resin was enhanced, and the adhesive properties of the composite were improved. X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrum (EDS) results of the fiber treated by Corona-PG-2S shows that the surface oxygen content was up to 25.0 wt %, with an increase of 17.3 wt % compared with the surface oxygen content of unmodified UHMWPE fiber, which indicated that the surface polarity was greatly enhanced. The adhesive properties were improved by improving the polarity of the surface. The peel strength, ultimate cohesive force, tensile strength and flexural strength of the composite treated by Corona-PG-2S were greatly increased to 262.8%, 166.9%, 139.7%, 200.6% compared with those of unmodified samples. The composite prepared by Corona-PG-2S had excellent adhesive properties, demonstrating that the Corona-PG-2S method plays a major role in significantly improving the composite adhesive properties.Keywords:UHMWPE fiber;epoxy resin;PVA;adhesive property;aldol condensation
研究领域:
材料科学
·
复合材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2020
·
IF 4.794
Xiaowei Fang,Ze Wang,Wenli Song,Songgeng Li
In this paper the aldol condensation of furfural (C5) with acetone (C3) over Ca/ZSM-5 was studied with lower dosages of water and acetone as compared to previous studies. It was observed that the formation of CaO over the catalyst is critical to catalyst activity and that the reaction may not occur without water. Although higher quantity of water was favorable for the formation of 4-(2-Furyl)-3-buten-2-one (C8), it was inhibitive for the formation of 1,5-bis-(2-furanyl)-1,4-pentadien-3-one (C13). Highest yields of C8 (38.4 mol%) and C13 (60.2 mol%) were obtained with C3-to-C5 mole ratio of 0.8:1, and water content of 29.7 wt%. The deactivated catalyst was further regenerated by re-loading CaO. An intrinsic kinetic model was established whereby the reaction was first-order dependent on the concentration of each reactant. The formation of 4-(2-furyl)-4‑hydroxy‑butan-2-one (C8-OH), and the C8-OH-to-C8 dehydration were essential steps. The reaction of C8-OH with C5 owned the highest activation energy (41.9 kJ/mol), this step was more sensitive to reaction temperature than those of other steps.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2022
·
IF 6.449
Shanshan Shao,Laixin Ma,Xiaohua Li,Huiyan Zhang,Rui Xiao
Heavy bio-oil based carbon material (HBC) was prepared via carbonization and activation, and the basic Mg-Al-O/HBC using HBC as the carrier was synthesized for the first time for the aldol condensation of cyclopentanone to produce aviation fuel precursor. It revealed that a higher carbonization temperature and heating rate led to the decreasing production of biochar. HBC presented the highest specific surface area (2046.92 m 2 /g) and total pore volume (1.2964 cm 3 /g) at the carbonization temperature of 700 °C, the heating rate of 15 °C/min, A/C ratio of 3:1, and the activation temperature of 800 °C, in which the largest proportion of micropores was 87.19%. Compared with Mg-Al-O, a higher strength of weak and moderate basic sites was found in Mg-Al-O/HBC, which was beneficial for the aldol condensation. A higher yield of targeted condensates in the range of C9∼C16 was achieved at 87.28% in the aldol condensation of cyclopentanone over Mg-Al-O/HBC catalyst. However, the condensation performance of the composite catalysts decreased seriously in the 5th run, which was related closely to the appearance of boehmite AlO(OH) and the pore blockage of HBC. To match the basic catalyst and HBC carrier well from the viewpoint of pore property, Al ions were substituted with Zr ions, and the yield of the target condensates over Mg-Zr-O/HBC was kept stably at 72.07% at the fifth use. This study provides a unique, viable and effective method to produce porous carbon from heavy fraction of bio-oil as the carbon source, and also its good application in the production of high-valued fuels.
研究领域:
能源科学
·
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Ravi Balaga,Peifang Yan,Kishore Ramineni,Hong Du,Zhi Xia,Mahender Reddy Marri,Zongchao Conrad Zhang
Furfural is an important bio-based platform chemical in the production of valuable products such as biofuel intermediates and polymeric materials. In this work, isolated Zr on mesoporous silica catalysts at varied Zr loading were prepared and evaluated for aldol condensation of furfural with acetone to 4-(2-furyl)− 3-buten-2-one(FAc) and 1,5-bis-(2-furanyl)− 1,4-pentadien-3-one(F 2 Ac). A remarkable effect of the Zr loading on the catalyst performance is revealed. The catalysts are characterized by XRD, BET, NH 3 -TPD, Py-FTIR, XPS, UV–visible, and TGA. The connectivity of Zr was characterized by XPS and UV–visible spectroscopy. For the 25 wt% Zr loading, Zr is present predominantly as isolated monomeric species on mesoporous SiO 2 . The types and densities of different acid sites of the catalysts are measured with Py-FTIR analysis. The results show that isolated Zr on mesoporous SiO 2 enhanced Lewis acid site densities and exhibited superior catalytic activity for aldol condensation between furfural and acetone to produce FAc and F 2 Ac.
研究领域:
催化化学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2019
·
IF 3.021
Mingxue Su,Wenzhi Li,Qiaozhi Ma,Song Li,Tao Yang,Xiaomeng Dou
A water-tolerant, basic, and hierarchical MFI zeolite catalyst was synthesized and applied in the aldol condensation reaction between biomass-derived furfural and levulinic acid. The results showed that the addition of poly(diallyl dimethylammonium chloride) significantly affected the textural and acid–base properties of hierarchical zeolite, which subsequently influenced the catalytic performance of hierarchical zeolite. In the aqueous phase, potassium-modified, hierarchical MFI zeolite (K/H-MFI-n) was more active for aldol condensation between furfural and levulinic acid than the potassium-modified, conventional MFI zeolite (K/MFI). This was ascribed to higher basic sites density and improved diffusion limitation of K/H-MFI-n. A 70.6% yield of aldol condensation product was achieved with a complete conversion of furfural at 100 °C for 9 h by K/H-MFI-0.6. However, only 27.4% yield of aldol condensation product with 55.1% furfural conversion was obtained by K/MFI at the same condition. Two major isomeric aldol products, β-furfurylidenelevulinic acid and δ-furfurylidenelevulinic acid (β-FDLA and δ-FDLA), were obtained after acidification. K/H-MFI-n displayed an enhanced selectivity (54.9%) to δ-FDLA, owing to the stronger basicity of K/H-MFI-n. However, K/MFI showed a preferred selectivity to β-FDLA (42.7%), owing to the dominant Lewis acidity. Recyclability research showed that the catalytic performance of potassium-modified, hierarchical MFI zeolite was acceptable after five runs.
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
CATALYSIS LETTERS
·
2018
·Vol. 149
·期 2
·373-389
·
IF 2.911
He Teng,Qu Yixin,Wang Jidong
The catalytic performance of cesium oxide supported on three types of silica gel A-type (A-silica), B-type (B-silica) and C-type (C-silica) was tested for the aldol condensation of methyl acetate (Ma) and formaldehyde (FA) to methyl acrylate (MA). The catalysts were characterized using TEM, BET, XRD, FTIR, TG, XPS, and CO 2 -TPD and the reaction mechanisms were explored using DFT calculations. To obtain high selectivity of MA, appropriate amount of Cs loading is required since much higher loading of Cs leads to excessive decomposition of Ma and/or MA. On the Cs/silica, the Si–O–Cs species generated from the reaction of cesium oxide with silanol groups are the active sites as demonstrated by characterization and the DFT calculations. Silica gels with larger pore size and pore volume are preferred since these facilitate the contact of the reactants with active sites and provide higher capacity for accommodation of coke. As compared with Cs/SBA-15, Cs/B-silica seems more prospective for industrial application due to the lower cost of silica gel and even better performance. Graphical Abstract
研究领域:
催化化学
·
理论计算化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 41
·32826-32834
·
IF 3.84
Yanan Wang,Xuewei Lang,Guoqing Zhao,Huanhui Chen,Yiwei Fan,Linqing Yu,Xiuxiu Ma,Zhirong Zhu
A variety of cesium supported catalysts with amorphous SiO2 as a carrier were prepared by vacuum impregnation and ultrasonic impregnation methods, which were used for the synthesis of methyl acrylate by aldol condensation of methyl acetate and formaldehyde. The as-prepared catalysts were characterized by XRD, N2 adsorption–desorption, NH3-TPD, CO2-TPD, XPS, ICP and TG. The results indicated that the bifunctional Cs–La–Sb/SiO2 showed a high conversion of methyl acetate as well as a high yield of methyl acrylate, which was attributed to the weak acid–base sites and the formation of basic Cs–O–Si species with the addition of antimony and lanthanum, respectively. Furthermore, Cs–La–Sb/SiO2-(V) prepared by vacuum impregnation showed a high initial catalytic activity, but its activity sharply decreased due to the loss of active species. Comparatively, Cs–La–Sb/SiO2-(U) prepared by ultrasonic impregnation showed a good stability owing to the cavitation effect of ultrasonic waves. The conversion of methyl acetate and yield of methyl acrylate remained above 20% and 9.0% (based on methyl acetate) for 100 h without obvious deactivation. Moreover, carbon deposition was the main factor for the deactivation of Cs–La–Sb/SiO2-(U), and the coked catalyst could be regenerated by calcination in air.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Yanan Liu,Genkuo Nie,Shitao Yu,Lun Pan,Li Wang,Xiangwen Zhang,Chengxiang Shi,Ji-Jun Zou
Synthesizing high-performance jet fuels from lignocellulose-derived ketones through aldol condensation is significant for expanding the sources of jet fuel and promoting high-value conversion of biomass. The main problem in aldol condensation is that water generated in such a reaction will decrease the activity of the acid catalyst. Herein, we developed a highly stable, efficient, and water-tolerant SBA-16 confined phosphotungstic acid (HPW) catalyst and applied it to controllably catalyze cross-condensation of cyclopentanone and cyclohexanone. The surface of SBA-16 was modified by alkylimidazole, which creates a relatively hydrophobic environment and anchor points for HPW, leading to resistance to HPW leaching and maintenance of a stable performance for the catalyst. After hydrodeoxygenation, a high-performance fuel blend with a density of approximately 0.905 g/mL and a freezing point lower than −50 °C was obtained. This study provides a general method for preparing highly efficient and stable catalysts for reactions affected by water.
研究领域:
生物质能
·
催化化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 16
·3555-3561
·
IF 5.773
Mingxue Su,Wenzhi Li,Tingwei Zhang,HaoSheng Xin,Song Li,Wei Fan,Longlong Ma
Aldol condensation reactions between furfural and acetone can be used to produce liquid fuel intermediates. It was found that tin-containing zeolites with MFI (Sn-MFI) and BEA* (Sn-Beta) framework structures are effective for C–C bond formation via the aldol condensation reactions between furfural and acetone. Aldol condensation between furfural and acetone produced two main products, 4-(2-furyl)-3-buten-2-one (FAc) and 1,5-di-2-furanyl-1,4-pentadien-3-one (F2Ac). Although both these catalysts were active for the aldol condensation reactions, different selectivities to aldol products were observed over Sn-MFI and Sn-Beta. FAc and F2Ac were formed over the Sn-Beta catalyst with selectivities to FAc of 40% and F2Ac of 22%, respectively. In contrast, only FAc was produced over Sn-MFI. The variation in selectivity is likely due to different pore geometries of Sn-Beta and Sn-MFI, suggesting that Sn-MFI exhibits shape selectivity for aldol condensation between furfural and acetone. In addition, it was found that the addition of water to the reaction system can also affect the product selectivity, leading to the aldol product exclusively being FAc over Sn-Beta.
研究领域:
化学工程
·
催化科学
·
可再生能源
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2020
·
IF 6.395
Jiajun Liu,Kui Wu,Zhengke Li,Wensong Li,Yuqing Ning,Weiyan Wang,Yunquan Yang
The great challenge in the aldol condensation of tailored fermentation products (acetone–butanol–ethanol, ABE) into energy intensive fuels is to develop a suitable catalyst with high activity and low–cost. In this study, Co, Ni, and Co–Ni supported on Mg–Al oxide catalysts were prepared and their pore diameters were enlarged via adding active carbon as a hard template into Mg–Al hydrotalcite. During the aldol condensation reaction, the catalyst activity was enhanced after enlarging the pore diameter and Co–Ni bimetal supported catalyst presented the highest activity, which was resulted from that the electron transfer between Co and Ni in Co–Ni alloy enhanced the dehydrogenation activity and large pore lowered the mass transfer resistance. After optimizing the reaction conditions, acetone conversion and the total selectivity of C 5 –C 11 desired products in the aldol condensation of ABE reached up to 76% and 90%, respectively. The stability study showed that the activity was decreased with the increase of reaction number because of the oxidation of metallic Co and Ni, but this could be solved via a simple hydrogen reduction method.
研究领域:
催化化学
·
能源科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Xiaohua Li,Jiayuan Sun,Shanshan Shao,Xinggang Hu,Yixi Cai
A one-pot method for jet fuel based on biomass-derived ketone platform compound has been developed through aldol condensation and hydrogenation over bifunctional catalysts . In this study, the problem of poor reusability of catalysts and the side reaction of hydrogenation could be solved effectively. Organic solvents were added into the reaction to reduce the contact between the catalysts and water. In the reusability tests, the yield of targeted hydrocarbons remained around 70% in 5 runs with the optimized cyclopentanone/n-pentane volume ratio of 1:2. With the hydrogen being introduced first, the condensation and hydrogenation were integrated into one step. Considering that part of cyclopentanone was hydrogenated directly, a method of low-temperature condensation (170 °C) and high-temperature hydrogenation (260 °C) was proposed. The temperature at each stage of the reaction was controlled strictly and the total yield of targeted alkanes was boosted by 6.3% compared with that in one-step method. By the design of the reaction process with bifunctional catalyst in one pot, it will promote the development of aviation fuel from biomass in a more sustainable and greener way.
研究领域:
生物化学
·
催化化学
·
可再生能源
✓ 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）