JOURNAL OF MATERIALS SCIENCE
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2017
·Vol. 53
·期 7
·4927-4938
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IF 2.599
Liu Ran,Zhang Juan,Xu Zhice,Zhao Dishun,Sun Shuang
Iron phthalocyanine (PcFe) was loaded on Ti-MCM-41 as visible light photocatalyst (R-PcFe/Ti-MCM-41). Dibenzothiophene (DBT) was photooxidized using R-PcFe/Ti-MCM-41 as a photocatalyst, air as an oxidant, and ionic liquid as the extraction agent during visible light irradiation at room temperature and ambient conditions. The results indicated that photocatalytic efficiency of the amino iron phthalocyanine (NH 2 -PcFe)/Ti-MCM-41 was superior to the other substituent groups. The DBT content in the model oil decreased from 1000 to 44 μg/mL with 95.6% removal rate under the optimal reaction conditions (model oil 10 mL, photocatalyst NH 2 -PcFe/Ti-MCM-41 0.02 g, loading amount of NH 2 -PcFe 0.3 g/g, air flow rate 100 mL/min, reaction time 2 h, room temperature). The kinetics of photocatalytic oxidation of DBT follows first-order kinetics with a rate constant of 1.319 h −1 and halftime of 0.525 h. The photocatalyst NH 2 -PcFe/Ti-MCM-41 was reused for five times, and the catalytic activity decreased slightly. The photocatalytic oxidation system demonstrated significant desulfurization effects on different sulfur compounds and real gasoline, and the sulfur content of the actual gasoline could be reduced from 1000 to 78 ppm.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 29
·15216-15224
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IF 3.708
Chong-Wen Jiang,Xin Zhong,Zheng-Hong Luo
5-Hydroxymethylfurfural (5-HMF) which can be produced from cellulose is considered as one of the promising green platform chemicals. In this work, the conversion of cellulose to 5-HMF was carried out through hydrolysis in a batch reactor using the SO42−/Ti-MCM-41 catalyst at a temperature of 463–503 K. Two analytical techniques including the 3,5-dinitrosalicylic acid (DNS) method and high performance liquid chromatography (HPLC) were employed to track the time evolution of the main reagents, i.e., cellulose, 5-HMF and reducing sugar. Based on the typical kinetic experiments for the cellulose hydrolysis, a comprehensive hydrolysis mechanism was introduced to describe the heterogeneous hydrolysis of cellulose to 5-HMF. A corresponding kinetic model was proposed on the basis of the hydrolysis mechanism and the mass balance law. The results show that the predicted data obtained via the suggested model agree well with the experimental results. In addition, some data from the open reports were referred for further model verification in this work. The kinetic model suggested in this work is a mechanism model for the heterogeneous catalytic cellulose hydrolysis process, which is different from the previous first-order kinetic model.
研究领域:
化学工程
·
可再生化学
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产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2024
·
IF 4.8
Guojun Lv,Xuyang Zou,Yan Chen,Qing Zhang,Xubin Zhang,Fumin Wang
The successful one-pot synthesis of MCM-41/MFI composite is mainly concentrated on the trivalent heteroatom of Al 3+ and Fe 3+ , however there are almost no reports about the one-pot synthesis of Ti-MCM-41/MFI composite. In this work, we reported the one-pot synthesis of Ti-MCM-41/MFI composite with a temperature-gradient hydrothermal strategy using hexadecyl trimethylammonium bromide CTAB and silicalite-1 seed as structure directing agents as well as ammonia solution as alkali source, and its application as heterogeneous catalyst in the cyclohexene epoxidation reactions. The impact of Si/Ti molar ratio and ammonia dosage as well as CTAB amount on the formation and property of Ti-MCM-41/MFI composite were systematically investigated. In addition, a possible partial transformation mechanism of Ti-MCM-41/MFI composite sample was proposed. The synthesized Ti-HMZ-50-N3.77-Se0.05 sample with ordered mesoporous structure and high content of framework titanium active centers revealed the eminent cyclohexene epoxidation performance, achieving a 32.51 % of cyclohexene conversion and a 61.27 % selectivity of cyclohexene oxide within 5 h of reaction.
研究领域:
催化化学
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材料化学
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纳米材料
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多相催化
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绿色化学
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Jianyun Yang,Yaoxing Xiang,Jisheng Xu,Chengxiang Shi,Lun Pan,Xiangwen Zhang,Ji-Jun Zou
Oxidative desulfurization (ODS) is a promising technology for removing sulfur compounds from fuel oil under mild conditions. This study prepared Ti/MCM-41 catalyst using a simple adsorption-hydrolysis-argon calcination method and applied it to ODS. Carbon introduced by tetrabutyl titanate (TBOT) and generated by calcination in inert atmosphere restrains the growth of TiO 2 , thereby promoting the formation of a high-activity Si-O-Ti structure. By using the optimal Ti/MCM-41 catalyst, desulfurization rate of model oil (dibenzothiophene dissolved in decalin, 500 ppm of sulfur) as high as 99.8 % was achieved at 40 °C with methanol as extractant and H 2 O 2 as oxidant (O/S = 4). After six recycles, the S removal rate was still 97.9 %. Reaction conditions like reaction temperature and extractant were carefully analyzed to explore the active structure and reaction mechanism, deducing that Si-O-Ti species promote the reaction probably by forming highly active bis-hydroperoxo Ti species with five-membered ring structure. Moreover, the promotion of methanol effect was found and reasonably explained. This work provides important guidance to the design of new catalysts, selection of extractant and optimization of oxidant for more efficient phase-transfer extractive and catalytic oxidation desulfurization (ECODS) process.
研究领域:
催化化学
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环境工程
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
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2013
·
IF 2.024
Dewen He,Cancheng Bai,Chongwen Jiang,Tao Zhou
Titanium containing MCM-41 is synthesized hydrothermally in the presence of structure-directing agent cetyltrimethylammonium bromide (CTAB). Bi- and tri-metal Fe and Zn are impregnated in these materials to improve the acid catalytic sites as well. XRD , BET nitrogen adsorption isotherm, TEM and SEM analysis confirm the presence of mesopores in the composite. The local environment of titanium incorporated into the mesoporous silicate material is investigated by FT-IR and UV–Vis spectroscopy. These results indicate the presence of active centers within the composite material Ti, Fe and Zn. The new composite materials are preliminarily tested in the hydrolysis of cellulose . All the titanium MCM-41 materials improve the conversion of cellulose, providing higher catalytic activity in hydrolysis. There is maximum sugar and 5-HMF concentration resulted from hydrolysis of cellulose with Fe/Ti-MCM-41 catalyst.
研究领域:
材料科学
·
催化化学
✓ 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）