Molecular Catalysis
·
2024
·
IF 3.9
Jiaqi Zhou,Qingrong Wang,Hong Liu,Ming Bao,Jiasheng Wang
Gas-phase selective oxidation of toluene with air is a promising method for producing high-purity benzaldehyde, but the yields of existing catalysts are limited, so the development of more efficient catalysts is of great importance to the chemical industry. Herein VMoNb/CeO 2 was prepared and characterized by SEM, XRD, Raman, XPS, H 2 -TPR, and NH 3 -TPD. The introduction of Mo generated V–O–Mo “asymmetric lattice oxygen” and thus brought high activity. Nb moderated the acidity and oxygen vacancy so as to improve the selectivity. The VMoNb/CeO 2 catalyst showed very high catalytic activity at 500 °C, with 35% toluene conversion and 82% benzaldehyde selectivity at an air flow rate of 30 mL/min for V:Mo:Nb =2:5:0.8. This work could serve as a reference for designing mixed metal oxide catalysts for selective oxidation of aromatic hydrocarbons.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2014
·Vol. 113
·期 2
·605-614
·
IF 0.983
Liu Hong,Yang Guohai
Gas-phase transformation of toluene is carried out on Cs-exchanged NaY zeolite in a fixed-bed tubular reactor and it is observed that toluene can transform through dealkylation, producing benzene and a small amount of hydrogen under the experimental conditions. After a definite activation period, the transformation of toluene can achieve its steady state with the yield of benzene above 25 % for a relatively long continuous time at low space velocity. Combining the results of characterization and catalytic performances, it can be concluded that benzene is the steadiest product except the carbonaceous residues within the CsY zeolite pores. The in situ carbonaceous deposition experiment shows a similar trend of the carbonaceous forming process and the yield of benzene, indicating the important role of carbonaceous species in the formation of benzene, i.e., it is necessary for the accumulation of carbonaceous species in the initial stage of reaction. The discovery in the current work sheds light on new strategies for the transformation of other similar compounds.
研究领域:
催化化学
·
材料化学
·
物理化学
·
能源化学
·
工业催化
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 21
·8126-8134
·
IF 0
Chen Chen,Song Shi,Min Wang,Hong Ma,Lipeng Zhou,Jie Xu
A surface organic modification strategy is utilized to design and prepare a series of superhydrophobic SiO2-based nanocomposites with cobalt ions in the bulk phase and different organic groups on the surface. Physical properties such as BET surface area, surface hydrophilicity/hydrophobicity, and water adsorption amount changed significantly with the introduction of organic groups of various chain lengths, which was confirmed by TEM, SEM, FTIR, 29Si-NMR, N2 adsorption–desorption, sessile water contact angle, and TG-DTA measurements. Surface hydrophilicity/hydrophobicity altered from hydrophilic to superhydrophobic with an increase in carbon chain length, which showed an obvious effect on the catalytic performance in selective oxidation of hydrocarbons such as ethylbenzene. Superhydrophobicity was guaranteed for high catalytic activity, and the carbon chain length of the organic group was also an important factor. Superhydrophobic Pr–Co–SiO2 that contained the propyl group was the most efficient catalyst, and the conversion of ethylbenzene reached 70.4% with O2 as an oxidant under solvent-free conditions at 393 K for 7 h, which is nearly nine times that of the hydrophilic Co–SiO2 without surface organic modification.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Ganhua Qiu,Ting Wang,Xiaoli Li,Xueqin Tao,Benxia Li
A heterostructure photocatalyst consisting of BiOCl nanoplates and a bismuth-organic hybrid layer (alias BiCl3Br–CTA) was synthesized through a one-step solvothermal process. The BiOCl/BiCl3Br–CTA heterostructures exhibited broad light absorption and enhanced electron–hole separation efficiency. Moreover, the abundant oxygen vacancies (OVs) and superoleophilic surface endowed the photocatalyst with high abilities for adsorption and activation of O2 and toluene. Therefore, the BiOCl/BiCl3Br–CTA photocatalyst showed excellent activities for the C(sp3)–H bond oxidation of toluene under full-spectrum irradiation and visible light of simulated sunlight, which are 6.8-fold and 237.8-fold, respectively, than those of BiOCl nanoplates. The photocatalytic mechanism was revealed by a series of controlled experiments and in situ ESR detections. The selective oxidation of toluene was promoted by the synergy between the electrons in BiOCl for activating O2 and the holes in the BiCl3Br–CTA layer for activating the C(sp3)–H bonds. This research demonstrates an effective strategy to construct high-activity photocatalysts for challenging organic transformations.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2013
·Vol. 5
·期 6
·1517-1523
·
IF 5.181
Yan Liu,Xiaozhao Zhou,Xinmei Pang,Yinying Jin,Xiangju Meng,Xiaoming Zheng,Xionghou Gao,Feng-Shou Xiao
Graphical Join the chain gang: Chain-like ZSM-5 crystals that are synthesized in the presence of starch show higher p -xylene selectivity in m -xylene isomerization than normal, mesoporous, and sheet-like ZSM-5 crystals. ZSM-5 zeolite crystals with controllable b- axis length (sheet-like, S-ZSM-5; chain-like, C-ZSM-5) have been synthesized by using urea and starch as additives in the starting aluminosilicate gels. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images show that these zeolite samples have good crystallinity. Transmission electron microscopy (TEM) images show that there is a strong chemical interaction between the stacked crystals in C-ZSM-5 samples. N 2 sorption isotherms indicate that C-ZSM-5 crystals are mesoporous. Catalytic tests for the formation of p -xylene from m- xylene isomerization show that, compared with other zeolite catalysts, C-ZSM-5 catalysts give both high conversion and improved p -xylene selectivity, which are attributed to the combination of relatively long b -axis length and the present mesoporosity in the crystals. The improvement of p -xylene selectivity in catalytic m- xylene isomerisation is of great importance for selective industrial production of p -xylene in the future.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2022
·Vol. 38
·期 5
·1258-1262
·
IF 2.726
Zhang Xingcong,Zhong Yunzhu,Chen Hongyu,Cheng Yujie,Sun Qingdi,Zhang Hao,He Qian,Zhang Ying,Guo Guanghui,He Xiaohui,Ji Hongbing
Through screening Ce precursors and pyrolysis temperatures [Ce(acac) 3 as Ce precursors and pyrolysis at 900 °C], zeolitic imidazolate framework-8(ZIF-8) derived nitrogen-doped carbon supported cerium single atom catalyst(Ce 1 /NC) is successfully prepared by ball milling method. The Ce 1 /NC catalyst exhibits exceptional catalytic performance in the selective oxidation of saturated C-H bonds in aromatic compounds, e.g. , 91% conversion and 99% selelctivity can be achieved in the oxidation of ethylbenzene to acetophenone under mild reaction conditions.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Jing Cao,Kejun Chen,Fangmei Teng,Jialing Liu,Xinyi Liu,Cen Zhang
Maximizing the exposure of edge sites and achieving sufficient promotion remain arduous tasks for designing efficient bimetallic MoS2-based catalysts. Herein, ultrathin CoMoS nanosheets vertically grown on reduced graphene oxide (CoMoS/rGO–DMF) were fabricated by a facile one-pot solvothermal method using dimethylformamide (DMF) as solvent. The vertically aligned structure and good Co promotion endow CoMoS/rGO–DMF with abundant Co–Mo–S active sites and excellent catalytic performance in the hydrodeoxygenation (HDO) reaction. Consequently, CoMoS/rGO–DMF afforded a conversion of 98.2% and a toluene selectivity of 98.8% at 240 °C, 3.0 MPa, and 4 h in the HDO of 4-methylphenol. In addition, CoMoS/rGO–DMF showed a 3-fold larger turnover frequency value than that of CoMoS/rGO–DW prepared in deionized water. The reusability test of CoMoS/rGO–DMF showed a slight activity loss after six catalytic cycles, which resulted from the surface oxidation by water product, but the HDO performance of the spent catalyst can be easily regenerated by a simple sulfidation process. This work provides new insights for the rational design of sulfide catalysts with excellent HDO activity and arene selectivity.
研究领域:
催化化学
·
材料科学
·
能源化工
·
纳米材料
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Results in Engineering
·
2023
·
IF 5
Yeqing Huang,Manna Wang,Yi Huang,Jin Shang,Baoyu Liu
The distribution of Brønsted acid sites in three-dimensional 12-membered pore channels of Beta zeolite was a decisive factor in the alkylation of benzene with cyclohexene. Here, the Brønsted acid site distribution in Beta zeolitic channels was precisely regulated by tuning the content of Na + in crystallization system combined with tetraethylammonium cation, the Beta-55 with Brønsted acid sites exclusively located in straight channels (along a - and b -axis directions) was successfully synthesized by utilizing tetraethylammonium as the structure-directing agents without Na + species, and the fraction of Brønsted acid sites in sinusoidal/straight channels of Beta zeolites can be accurately controlled by tailoring the content of Na + in synthesis gel. Catalytic properties in the liquid alkylation between benzene and cyclohexene exhibited that Beta-55 zeolites with the Brønsted acid sites solely located in a -axis and b -axis channels showed the highest cyclohexene conversion, cyclohexylbenzene selectivity and longest lifetime in this reaction. In addition, the resultant Beta zeolites also exhibited low coke generation rate and robust regeneration performance in the alkylation reaction.
研究领域:
催化
·
化学工程
·
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）