APPLIED CATALYSIS A-GENERAL
·
2023
·
IF 5.5
Jiasheng Wang,Qingrong Wang,Mengdi Zhao,Ming Bao
Toluene gas-phase oxidation is a green, chlorine-free production process for benzaldehyde but its conversion efficiency is still unsatisfying due to the lack of highly efficient catalyst. Here the selective oxidation of toluene to benzaldehyde over V-Ag-Ce/TiO 2 under an air atmosphere was investigated. The catalyst was prepared by impregnation and characterized by scanning electron microscope (SEM), N 2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), H 2 temperature programmed reduction (H 2 -TPR), O 2 temperature programmed desorption (O 2 -TPD), and NH 3 temperature programmed desorption (NH 3 -TPD). The amount of oxygen vacancy and acid of the catalyst can be tuned through adjusting the V:Ag:Ce ratio. Over the optimum catalyst (V:Ag:Ce = 4:2:1, molar ratio), 92% benzaldehyde selectivity with a 27% toluene conversion can be obtained at 550 °C. Medium amounts of oxygen vacancy (0.43) and acidity (0.10 mmol/g) are found to be conducive to the conversion of toluene to benzaldehyde. This study has important theoretical guiding significance for improving conversion efficiency from toluene to benzaldehyde by gas-phase aerobic oxidation.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 15
·8743
·
IF 6.208
Baojuan Deng,Yadan Luo,Meijiao Peng,Tao Li,Jianwei Su,Yang Wang,Xuelian Xia,Chengqi Feng,Shuangquan Yao
As a green and efficient component separation technology, organic acid pretreatment has been widely studied in biomass refining. In particular, the efficient separation of lignin byp-toluenesulfonic acid (p-TsOH) pretreatment has been achieved. In this study, the mechanism of the atmospheric separation of bagasse lignin withp-TsOH was investigated. The separation kinetics of lignin was analyzed. A non-simple linear relationship was found between the separation yield of lignin and the concentration ofp-TsOH, the temperature and the stirring speed. The shrinking nucleus model for the separation of lignin was established based on the introduction of mass transfer and diffusion factors. A general model of the total delignification rate was obtained. The results showed that the process of lignin separation occurred into two phases, i.e., a fast stage and a slow stage. The results provide a theoretical basis for the efficient separation of lignin byp-TsOH pretreatment.Keywords:p-toluenesulfonic;lignin;mechanism;kinetics;shrinking nucleus model
研究领域:
生物质能
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2024
·
IF 5.6
Ni Wei,Xin Xu,Jiushun Qin,Wei Lai,Ruoyan Li,Chenhuan Lai,Qiang Yong
Development of green pretreatment strategies with excellent lignin removal ability is particularly important for masson pine biorefinery. γ-Valerolactone (GVL), as a green and recyclable solvent, has unique solvent characteristics to extract lignin. In this study, three acid catalysts, including sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl) and p -toluenesulfonic acid (TsOH), were used to catalyze γ-valerolactone (GVL) pretreatment of masson pine. Among them, the TsOH-catalyzed GVL pretreatment achieved the highest lignin removal ratio and the best cellulose enzymatic hydrolysis yield. Under the optimized pretreatment conditions (150 ℃, 150 mM TsOH, GVL/H 2 O (4:1, w/w), 1 h), the lignin removal ratio reached 89.0 %, achieving a 72 h glucose yield of 87.1 % from the pretreated residues. The solvent lignins from pretreatment liquid was separated and characterized by NMR analysis. Meanwhile, the hexoses in pretreatment liquid were further converted into levulinic acid (LA) using the TsOH-catalyzed bi-phase reaction systems. This study gives insights into developing a biorefining process for the effective utilization of masson pine.
研究领域:
生物化学
·
生物质能工程
✓ 已验证
产品关联
DOI
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2018
·Vol. 96
·期 11
·2443-2449
·
IF 1.265
Jiaming Xue,Zuoxiang Zeng,Weilan Xue,Huayu Yang
The kinetics of the esterification between benzoic acid and isoamyl alcohol has been studied using p -toluenesulphonic acid as a catalyst. The conversion of the benzoic acid was determined by following the concentration of water measured with a Karl Fischer titrator. The effects of the reaction temperature, catalyst concentration, and initial acid to alcohol molar ratio on reaction kinetics have been examined. A five-step assumption was proposed to describe the reaction mechanism for the formation of isoamyl benzoate. And the kinetic model derived from the proposed mechanism can fit well with experimental kinetic data of the esterification, which indicates that the proposed mechanism is reasonable. The nonideality of the liquid reaction mixture has been considered and the activity coefficients of all components were estimated by the UNIFAC model. The reaction rate constants from 353.15 K to 383.15 K have been determined through the least square method. Meanwhile the activation energy and the standard enthalpy change of reaction in the presence of p -toluenesulphonic acid were calculated to be 50.45 kJ/mol and −3.75 kJ/mol respectively.
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
BIORESOURCE TECHNOLOGY
·
2023
·
IF 11.4
Meixin Wang,Yawei Zhan,Jiayue Zhao,Zhiqiang Li
Bamboo and its mechanical processing residues have broad prospects for high value-added utilization. In this research, p-toluenesulfonic acid was used for the pretreatment of bamboo to investigate the effects of extraction and depolymerization of hemicellulose. The response and behavior of changes of cell-wall chemical components were investigated after different solvent concentration, time, and temperature pretreatment. Results indicated that the maximum extraction yield of hemicellulose was 95.16 % with 5 % p-toluenesulfonic acid at 140 °C for 30 min. The depolymerized components of hemicellulose in the filtrate were mainly xylose and xylooligosaccharide, with xylobiose accounting for 30.77 %. The extraction of xylose from the filtrate reached a maximum of 90.16 % with 5 % p-toluenesulfonic acid at 150 °C for 30 min pretreatment. This research provided a potential strategy for the industrial production of xylose and xylooligosaccharide from bamboo and for the future conversion and utilization.
研究领域:
生物质利用
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Qiumu Lin,Xiaoge Ji,Shijing Sun,Zhongyuan Zhao
Driven by sustainable development goals, the wood-based panel industry increasingly favors renewable biomass-based and formaldehyde-free adhesives. Saccharides, owing to their renewable environmental friendliness and high reactivity, have garnered attention for green adhesive development. However, existing saccharide-based adhesives face challenges due to demanding curing conditions (hot-pressing temperature ≥160 °C), limiting their industrial application. In this study, a fructose and toluene-4-sulfonic acid adhesive (FT adhesive) was prepared by a simple one-pot process. FT adhesive can be hot-pressed at 110 °C to prepare plywood in line with the China National Standard GB/T 9846–2015 (wet strength ≥0.7 MPa). Compared with other saccharide-based adhesives, FT adhesives show superior curing efficiency while maintaining high bonding strength. During the synthesis phase, fructose reacts with toluene-4-sulfonic acid at lower temperatures to produce various active compounds, including 5-HMF and its derivatives, formic acid, acetic acid, and furan compounds. These compounds undergo condensation reactions during high-temperature curing, forming polyfurans, humin polymers, and other insoluble polymers predominantly bonded by C–O–C, C–O, and C═O linkages. Additionally, toluene-4-sulfonic acid acts as a catalyst and an enhancer in both synthesis and curing phases, facilitating the conversion and cross-linking of 5-HMF and its derivatives. This process results in a robust and dense network structure, significantly enhancing the adhesive performance of FT adhesives at lower curing temperatures (110–130 °C). This research offers insights into the development of efficient and environmentally friendly saccharide-adhesives for wood-based panels.
研究领域:
材料科学
·
可持续发展
·
林业工程
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Meijiao Peng,Jiatian Zhu,Yadan Luo,Tao Li,Xuelian Xia,Chengrong Qin,Chen Liang,Huiyang Bian,Shuangquan Yao
The cellulose-rich residual solids are obtained with p -toluenesulfonic acid ( p -TsOH) treatment. However, better fractionation of hemicellulose and separation is difficult to obtain during treatment. This study aims at investigating the separation selectivity of bamboo hemicellulose using freeze–thaw-assisted p -TsOH (F/ p -TsOH) treatment. The desired separation effect was achieved at freezing temperature −40 °C, freezing time 20 h, p -TsOH concentration 3.0 %, treatment temperature 130 °C and time 80 min. 93.26 % hemicellulose separation was found, which was 32.88 % higher than that of conventional p -TsOH treatment. Furthermore, the separation yield of lignin decreased significantly from 69.29 % to 13.98 %. The distinct lignin characteristic absorption peaks were found, while that of hemicellulose was difficult to observe. The fiber crystallinity index increased from 50.42 to 56.55 %. Furthermore, greater selectivity for hemicellulose separation was achieved. The results provide a new research thinking for efficient fractionation of lignocellulosic biomass by organic acid treatment.
研究领域:
生物质化学
·
林产化学工程
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2014
·
IF 0
Zhi Jia Luo,Hong Zhang Geng,Song Ting Zhang,Bao Tan Du,Xing Zhang,Jing Wang,Zhan Guo Lu,Su Jun Ma,Jin Qiu Zhang,Hai Jie Yang,Jie Wang
Graphene oxide (GO) is typically synthesized by graphite powder under strong oxidizing reaction, possessing with the same set of functional groups: epoxy and hydroxyl in basal plane and carboxyl and hydroxyl groups existence on the flake edges which endow GO with amphipathy. GO and its functionalized derivatives have been successfully tested in many domains, such as polymer composites, biosensors, drug delivery systems, etc. In this paper, GO was prepared by a modified Hummers method employing improved process (preparation and separation), aiming at industrialization with the lowest cost. Moreover, some novel functional groups with different properties were controlled chemically grafted onto GO to modify the wettability and reaction activity with other materials. The hydrophobicity and the thermal property of graphene oxide were enhanced by chemical functionalization.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Chengqi Feng,Jiatian Zhu,Yajun Hou,Chengrong Qin,Wangqian Chen,Yuhao Nong,Zhangpeng Liao,Chen Liang,Huiyang Bian,Shuangquan Yao
Hemicelluloses were effectively separated using p -toluenesulfonic acid ( p -TsOH) treatment at high temperature. High temperature and pressure promoted hydrolysis of hemicellulose, which limited its value upon recovery. In this study, bagasse hemicellulose was separated and extracted by p -TsOH treatment at atmospheric pressure. The effects of temperature, p -TsOH concentration, and time on hemicellulose separation and extraction were investigated. The optimal conditions were 80 °C, 3.0% p -TsOH, and 120 min. The separation and extraction yield of hemicellulose was 73.23% and 36.02%, respectively. Extraction hemicellulose with 95.60% purity was obtained. In addition, the dissolution mechanism of hemicellulose was analyzed. Degradation of β-glycosidic bonds was inhibited. Benzyl ether bond between carbohydrates and lignin was selectively cleaved. The skeleton structure of xylan in hemicellulose was protected while the functional groups of branch chain were severely damaged. It provides a valuable theoretical basis for the efficient separation and extraction of hemicellulose.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Communications
·
2025
·
IF 4.5
Xiao Wang,Xiaoyu Wang,Xiang Lu,Rongyan Hu,Yutong Li,Xinyi Wang,Shihao Ma,Zuguang Liu
With the rise of green chemistry and cleaner production, the carbon-based solid acids as environment-friendly catalysts have received increasing attention worldwide. In this paper, A composite catalyst was obtained by a combination of sulfonated glucose (SG) and p -toluenesulfonic acid (PT), and identified as a catalyst for the esterification reaction between α -pinene and acetic acid (AC). It is demonstrated that the composite catalyst, possessing a high density of active sites (1.59 mmol/g of sulfonic acid and 5.05 mmol/g of total acid, respectively) and mesoporous structure (5.7 nm), demonstrates outstanding catalytic activity with a conversion of α -pinene reaching 100 % and a selectivity of 51.2 % for total ester under optimum reaction conditions. Kinetic analysis shows that the esterification reaction behaves according to pseudo-first-order kinetics, featuring an activation energy of 135.86 kJ/mol. Moreover, the thermodynamic enthalpy (Δ H ) and Gibbs free energy (Δ G ) associated with the esterification reaction are 133.05 kJ/mol and 85.86 kJ/mol, respectively, implying that this reaction is endothermic and not spontaneous. Moreover, the catalyst has been shown to be reusable up to 4 times while retaining high catalytic activity. Overall, the catalyst has demonstrated significant potential as a heterogeneous catalyst for transforming α -pinene into valuable acetates.
研究领域:
绿色化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2023
·
IF 4
Zhang Hao,Zhang Xia,Li Wenzhi,Wu Wenjian,Tang Bingyue,Zhu Chen
Efficient extraction of lignin from intricate lignocellulose is a challenge for the high-value utilization of lignocellulosic biomass in sustainable biorefinery. In this work, a p -toluene sulfonic acid-coupling ethylene glycol (PTSA/EG) pretreatment was developed to extract lignin from cornstalks. The results showed that the synergistic effect between p -toluene sulfonic acid and ethylene glycol resulted in an increase in the delignification ratio from 43.43 to 85.37% compared with PTSA aqueous pretreatment. When the concentration of PTSA was 5 wt.%, the delignification ratio reached 85.37% at 383.15 K under the PTSA/EG pretreatment. Moreover, the lignin fractions obtained by water precipitation have high purity (>90%) and a low molecular weight (1777~2271 Da). The fractionated lignin was depolymerized with Ru/C catalyst and methanol at 508.15 K for 3 h. When the pretreatment temperature is 368.15 K, the fractionated lignin has a good depolymerization performance, and the detected monomers yield reaches 17.46%. Overall, pretreatment using PTSA and EG could realize the disruption of the degradation barrier of lignocellulose and fractionate lignin with specific structures by adjusting the pretreatment conditions, which was conducive to commercial applications in biomass refining.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2011
·
IF 3.074
Ting Wu,Xiang Cai,Shaozao Tan,Hongye Li,Jiesheng Liu,Weidong Yang
In order to explore the potential of graphene (G) in removal of hazardous chemicals in waste water, chemically reduced graphene oxide was employed as the adsorbent and the adsorption characteristics of graphene toward acrylonitrile (AN), p-toluenesulfonic acid (p-TA), 1-naphthalenesulfonic acid (1-NA) and methyl blue (MB) were evaluated under laboratory conditions. The results showed that the organic chemicals with larger molecule size and more benzene rings possessed a higher adsorption speed and a higher maximum adsorption capacity on G. The maximum adsorption capacities of p-TA, 1-NA and MB on G are ∼1.43 g/g G, ∼1.46 g/g G and ∼1.52 g/g G at 30 °C, respectively, which are the highest values of p-TA, 1-NA or MB adsorption on different kinds of today's nanomaterials. Under the maximum adsorption capacity, the absorption quantity of MB on G was dependent on the initial concentration of MB, and higher temperature could facilitate the adsorption process. The G efficiency remains almost constant during the first five cycles of the adsorption–desorption process. In addition, the fluorescence spectra implied that the adsorption of MB on G was a π–π stacking adsorption process. In conclusion, the G could serve as a promising adsorbent for the removal of chemicals containing benzene rings in waste water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）