MICROPOROUS AND MESOPOROUS MATERIALS
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2021
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IF 5.455
Zijun Yang,Qiang Yu,Yonghua Guo,Xiaoxia Wu,Hua Wang,Jinyu Han,Qingfeng Ge,Xinli Zhu
Heteroatom metal-zeolite, with heteroatom metal (oxide) dispersed in the zeolite framework, enables the reactions typically catalyzed by bulk metal oxide counterpart but with maximized the atomic utilization. However, the distribution of heteroatoms in the framework is strongly influenced by the preparation method. In this work, Ti-Beta zeolites were postsynthesized using the recrystallization (Ti-Beta-Re) and solid-state ion-exchange (Ti-Beta-SSIE) methods. Characterizations showed that more Ti species were incorporated in the tetrahedral framework site of Ti-Beta-Re to form Lewis acid sites than in that of Ti-Beta-SSIE. In addition, intra-crystallite mesopores were developed in Ti-Beta-Re due to partial dissolution of BEA framework during alkaline etching and subsequent recrystallization of the etched framework. These zeolites were then tested for ketonization of biomass derived propionic acid at 350 °C and atmospheric pressure. The turnover frequency of ketonization was found to be 25% higher on Ti-Beta-Re (0.25 min −1 ) than on Ti-Beta-SSIE (0.20 min −1 ), whereas the apparent activation energy of 80 kJ/mol on Ti-Beta-Re is lower than 95 kJ/mol on Ti-Beta-SSIE. Moreover, the selectivity of 3-pentanone kept > 95% on Ti-Beta-Re while it dropped to ∼63% on Ti-Beta-SSIE with increase of reaction time at a space time of 2 h. This work demonstrated that the tetrahedrally coordinated Ti species are the active sites and the presence of intra-crystallite mesopores facilitates selective ketonization of carboxylic acids.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
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IF 3.573
Shanshan Shao,Xianliang Xiang,Xiaohua Li,Huiyan Zhang,Rui Xiao,Yixi Cai
Acetic acid, n-butyraldehyde, furfural, n-butanol, and ethyl acetate as model compounds of biomass pyrolysis vapors were selected as reactants for ketonization over CeO2. Catalytic conversion of single components was conducted to understand their ketonization characteristics and also to obtain the overlapped temperature range. The results showed that the yield of acetone from directional ketonization of acetic acid reached a maximum of 97.4% at 360 °C over CeO2 with numerous oxygen vacancies, while n-butyraldehyde, n-butanol, and ethyl acetate performed the best at 420 °C with limited yield of ketones of 47.2, 35.1, and 85.4%, respectively. At the overlapped 420 °C, owing to the dehydration of acetic acid molecules, the ketonization of n-butyraldehyde was promoted with the largest overall yield of ketones of 96.5%. A mixture of furfural/acetic acid (1:4) brought about a lower yield of ketones of 78.8%, indicating a negative synergism due to active sites occupation by furfural adsorption.
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
FUEL
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2022
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IF 8.035
Wenran Gao,Yiling Wan,Shanhui Zhao,Muhammad Asif Akhtar,Kuan Ding,Bin Li,Yinlong Wu,Shoujun Zhang,Shu Zhang
Ketonization of biomass-derived oxygenates is promising for sustainable production of platform chemicals, but the catalyst activity will be severely inhibited by furanic compounds. To investigate the mechanism of the inhibition effect, furanic compounds with different side functional groups were chosen for co-ketonization with propanoic acid over CeO 2 . Results from 12 h continuous reaction showed that conversion of propanoic acid changed slightly when furan was co-fed with propanoic acid, while decreased significantly from 100 % for sole propanoic acid feeding to <55 % when co-feeding with furfural and furfuralcohol. Therefore, the inhibition ability followed the order of furfural ≈ furfuralcohol ≫ furan, which agreed well with the coke yield on the spent catalysts (51 %, 47 %, and 22 %, respectively). DFT calculation indicated that furfural and furfuralcohol, with the adsorption energy of 17–19 kJ·mol −1 , were much easier to adsorb on the catalyst than furan (11 kJ·mol −1 ). However, the lack of α-H of these furanic compounds led to their conversion into aromatic coke components. It is evidenced that the oxygenated side groups, rather than the furan ring, are responsible for the inhibition effect. Successive ketonization-combustion-ketonization tests revealed that simple air calcination can hardly recover the activity of the spent CeO 2 . This investigation gives new insights into the inhibitory impact of furans on the ketonization activity.
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
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IF 19.503
Jyoti Gupta,Konstantinos Papadikis,Elena Yu. Konysheva,Yi Lin,Ivan V. Kozhevnikov,Jingjing Li
The impact of CaO on oakwood pyrolysis was explored by the Py-GC/MS at 500 °C. Ca(OH) 2 presents on the CaO surface, indicating its partial hydration (noted as CaO OH ). CaO OH promoted the ketonisation of carboxylic acids to aliphatic ketones, furfural to cyclopentanone/2-cyclopentenone, facilitated the elimination of the methoxy-phenolic compounds. The catalyst loading did not show any significant effect on the formation of acetone, while a noticeable reduction in the phenolics was revealed. Increasing catalyst loading almost eliminated CO 2 , acids, furans, aldehydes, ether groups, whilst the fractions of alcohols, esters, sugars, and alkoxybenzene decreased noticeably. The use of partially hydrated CaO OH in the CFP can create conditions where by-products generated during the ketonisation and phenolics upgrading reactions (CO 2 , H 2 O, CO) interact through the adsorption enhance water-gas-shift reaction and through coking reactions with formation of H 2 used for hydrogenation during multistep conversion of furfural to cyclopentanone in a vapour phase.
研究领域:
能源化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Kejun Zhong,Jie Xiang,Yu Liu,Chuanlin Song,Yuetong Mu,Ting Yao,Kai Zhao,Tianfeng Gu,Pengxiang Jia,Wenyan Zhang
Conductive hydrogels have been widely applied in biomedical and wearable electronic devices due to outstanding physical properties such as electrical conductivity, excellent flexibility, and biocompatibility. However, the poor swelling resistance of conventional conductive hydrogels would lead to a significant decrease in their electrical conductivity and mechanical strength in wet or underwater environments, which largely limited their application. Here, a high strength, swelling resistance, and conductive hydrogel was prepared via the formation of ketals. First, ketalization between hydroxyethyl methacrylate (HEMA) and polyvinylpyrrolidone (PVP) was conducted using acid as the catalyst. Then, the hydrogel was fabricated through the polymerization of HEMA in the presence of polypyrrole (PPy). The resulting hydrogel showed high mechanical strength (the tensile strength was 557.7 kPa, and the breaking elongation was 451.4 %, the toughness was 1730.7 kJ/m 3 ), good conductivity (0.78 S/m) and swelling resistance (the equilibrium swelling rate was 21.1 %). In addition, the hydrogel displayed excellent stability and high sensitivity as an underwater strain sensor. It was also found that the hydrogel indicated voltage piezoresistivity, photo deformation performance, charge storage properties, and high sensitivity for heavy metal ion detection. Thus, the obtained hydrogel had a huge application potential for multifunctional flexible underwater sensors.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2025
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IF 9
Kuan Ding,Junheng Zhang,Deliang Xu,Jinfeng Hang,Félix Mérimée Bkangmo Kontchouo,Chanchana Thanachayanont,Thipjak Na Lampang,Zhaoyang Xu,Shu Zhang,Roger Ruan
Catalytic deoxygenation by ceria (CeO 2 ) represents an effective approach for upgrading bio-oil, yet the relationship between oxygen vacancies (O V ) of CeO 2 and catalytic ability remains controversial. To address this issue, three CeO 2 samples calcined in different atmospheres were adopted in catalytic deoxygenation of n -octanoic acid. Characterization results revealed that these CeO 2 exhibited identical crystal structure and different O V contents and surface acid-base properties. Catalytic tests demonstrated that O 2 -calcined CeO 2 primarily promoted ketone production at 400–600 °C while facilitated the formation of alkenes and aromatics at 600 °C. For the three CeO 2 catalysts, the highest O V content in H 2 -calcined CeO 2 endowed it with optimal acid-base pairs for enhancing both ketonization and aromatization reactions, thus achieving superior deoxygenation performance. Density functional theory calculations confirmed that O V significantly reduced the adsorption energy of active species during ketonization. This study provides evidence that surface O V of CeO 2 boost deoxygenation activity by optimizing acid-base pair sites.
研究领域:
催化化学
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能源化学
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表面科学
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生物质转化
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材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
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2025
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IF 4.8
Fei Jiang,Zhiming Dong,Xiaoli Lou,Zhuonan Zhang,Li Shuai,Chengke Zhao
Secondary benzyl alcohols (α-OH) in lignin β-O-4 linkages are reactive sites that can trigger undesirable condensation reactions during lignin valorization processes. The selective oxidation of α-OH groups can effectively inhibit lignin condensation reactions, thereby promoting lignin depolymerization. Meanwhile, this approach increases the functionalities, which is beneficial for the design of lignin-derived functional materials. In this study, we report a chemoselective oxidation method using 2-iodoxybenzoic acid (IBX) to selectively convert α-OH groups into ketones. The reaction proceeds under ambient conditions with green DMSO as the sole solvent. Oxidation of β–O–4 model compound (veratrylglycerol-β-guaiacyl ether, VG) revealed exceptional selectivity of this oxidation process, achieving 92% substrate conversion with 90% yield of the corresponding α-ketone product after 48 h. When applied to cellulolytic enzyme lignin, this protocol significantly increased the α-ketone content from 1.2% to 20.5% (relative to total interunit linkages), as identified and quantified by 2D HSQC NMR. The straightforward α-OH oxidation protocol demonstrates significant potential for precise lignin structure modification and rational design of lignin-derived functional materials in sustainable polymer systems.
研究领域:
高分子化学
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绿色化学
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生物质转化
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天然产物化学
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可持续材料
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有机合成方法学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
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2021
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IF 3.512
Yixuan Huang,Guangcai Zhang,Qinhui Zhang
In the present work, an efficient and stable WOX/MCM-41 solid acid catalyst was prepared by the wet impregnation method. The characterization of powder X-ray diffraction, transmission electron microscopy, ultraviolet–visible, H2 temperature-programmed reduction, X-ray photoelectron spectroscopy, NH3 temperature-programmed desorption, and N2 adsorption–desorption isotherms confirmed that the impregnation amount and calcination temperature of WOX speciation affected the dispersity and acidity of the resulting catalyst. This WOX/MCM-41 solid acid catalyst was subsequently applied in the ketalization reaction of glycerol and acetone to produce solketal. By catalyst screening and reaction condition optimization, WOX/MCM-41 obtained by impregnating 20 wt % and calcining at 350 °C exhibited the highest solketal yield and catalytic stability.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）