Preparation and Characterization of Ti-SBA-15 Mesoporous Materials with Varying Si/Ti Molar Ratios

2012 ◽  
Vol 482-484 ◽  
pp. 985-988
Author(s):  
Qiu Ying Huang ◽  
Wei Liu ◽  
Wen Hao Ye ◽  
Xiu Cheng Zheng
Keyword(s):  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
Catalytic Efficiency ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
Good Catalytic Activity ◽  
Epoxidation Of Cyclohexene

Ti-SBA-15 mesoporous materials with different Si/Ti molar ratios were synthesized via a hydrothermal process and characterized by using various techniques. The effect of Si/Ti molar ratios in the gels on the structure and catalytic efficiency in epoxidation of cyclohexene was discussed in details. The results showed that all the Ti-SBA-15 materials retained SBA-15 mesoporous structure and exhibited good catalytic activity. Furthermore,the sample prepared with Si/Ti =50 exhibited the best catalytic performance under the reaction conditions.

Synthesis, Characterization and Catalytic Efficiency of Ti-SBA-15 Mesoporous Materials

2011 ◽  
Vol 233-235 ◽  
pp. 2011-2014 ◽  
Author(s):  
Xiu Cheng Zheng ◽  
Wen Hao Ye ◽  
Zheng Lin ◽  
Bing Jie Liu ◽  
Xiao Juan Shi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
Catalytic Efficiency ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Epoxidation Of Cyclohexene

Ti-SBA-15 mesoporous materials were directly synthesized via a hydrothermal process and characterized by using nitrogen adsorption-desorption measurements, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, diffuse reflectance ultraviolet-visible spectroscopy, and infrared ray spectroscopy. The effect of synthesis temperatures on the structure and catalytic efficiency in epoxidation of cyclohexene was discussed in details. The results showed that the optimal temperature was 100 °C under the reaction conditions.

Alkali-hydrothermal synthesis and characterization of W-MCM-41 mesoporous materials with various Si/W molar ratios

2013 ◽  
Vol 270 ◽  
pp. 590-595 ◽  
Author(s):  
Hai-Yan Wu ◽  
Xiao-Li Zhang ◽  
Chun-Yan Yang ◽  
Xi Chen ◽  
Xiu-Cheng Zheng
Keyword(s):  
Hydrothermal Synthesis ◽  
Mesoporous Materials ◽  
Synthesis And Characterization ◽  
Molar Ratios ◽  
Mcm 41

Manganese meso-tetra-4-carboxyphenylporphyrin immobilized on MCM-41 as catalyst for oxidation of olefins with different oxygen donors in stoichiometric conditions

2012 ◽  
Vol 16 (03) ◽  
pp. 260-266 ◽  
Author(s):  
Saeed Rayati ◽  
Saeed Zakavi ◽  
Parisa Jafarzadeh ◽  
Omid Sadeghi ◽  
Mostafa M. Amini
Keyword(s):  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Significant Loss ◽  
Molar Ratios ◽  
Porphyrin Ligand ◽  
Tert Butyl Hydroperoxide ◽  
Oxidation Of Olefins ◽  
Oxygen Donors ◽  
Different Order ◽  
Mcm 41

Oxidation of olefins with tert-butyl hydroperoxide (TBHP), tetra-n-butylammonium periodate (TBAP) and potassium peroxomonosulfate (Oxone) in the presence of MCM-41 immobilized meso-tetra-4-carboxyphenylporphyrinatomanganese(III) acetate has been studied. The results of this study show better catalytic performance of the heterogonous catalyst using TBHP as oxidant in comparison with Oxone and TBAP in oxidation of the used olefins with the exception of cyclooctene. However, different order of reactivity of various olefins has been observed in the presence of Oxone and TBHP. In spite of the absence of good electron-withdrawing groups at the periphery of porphyrin ligand, the catalyst was recovered and reused (at least four times) without detectable catalyst leaching or a significant loss of the catalytic efficiency. All results have been obtained in the absence of using excess molar ratios of olefin to the oxidant, commonly employed as a strategy to overcome the instability of metalloporphyrins in oxidative conditions.

scholarly journals Synthesis and process optimization of Boscalid by catalyst Pd-PEPPSI-IPrDtBu-An

2021 ◽  
pp. 3-3
Author(s):  
Jian Xu ◽  
Xiao-Bing Lan ◽  
Lin-Jian Xia ◽  
Yi Yang ◽  
Gao Cao
Keyword(s):  
Raw Materials ◽  
Condensation Reaction ◽  
Suzuki Reaction ◽  
Coupling Reaction ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Synthesis Process ◽  
Reaction Conditions ◽  
Cross Coupling Reaction ◽  
Optimal Reaction

The purpose of this research was to reduce the amount of noble metal palladium catalyst and improve the catalytic performance in the Suzuki-Miyaura cross-coupling reaction, which is the key step in the synthesis of Boscalid. Taking o-bromonitrobenzene and p-chlorophenylboronic acid as raw materials, three kinds of Pd-PEPPSI-IPr catalysts were synthesized and employed in the Suzuki reaction, and then the biaryl product was subjected to reduction and condensation reaction to prepare Boscalid. Under optimal reaction conditions, the result showed that the catalytic system exhibits highest catalytic efficiency under aerobic conditions, giving the 2-(4-chlorophenyl)nitrobenzene over 99 % yield. Moreover, the Pd-PEPPSI-IPrDtBu-An catalyst was minimized to 0.01mol%. The synthesis process was mild, the post-treatment was simple, and the production cost was reduced which makes it suitable for industrial production.

Synthesis and Characterization of W-SBA-15 Mesoporous Material

2012 ◽  
Vol 485 ◽  
pp. 31-34 ◽  
Author(s):  
Bei Bei Dong ◽  
Ke Zhang ◽  
Cai Xia Li ◽  
Cheng Yuan Yuan ◽  
Xiu Cheng Zheng
Keyword(s):  
Organic Solvent ◽  
Mesoporous Material ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Synthesis And Characterization ◽  
Solvent Free Conditions ◽  
Sol Gel Process ◽  
One Step

W-SBA-15 mesoporous material was synthesized by using a one-step co-condensation sol-gel process and characterized by various methods. The results showed that the prepared W-SBA-15 sample retained the typical mesoporous structure of SBA-15 and exhibited good catalytic performance for the green synthesis of adipic acid under organic solvent-free conditions.

Preparation and Characterization of Silica-Based Mesoporous Materials

2011 ◽  
Vol 396-398 ◽  
pp. 463-467
Author(s):  
Xiao Hui Zhang ◽  
Qi Guang Cao ◽  
Guo Li Xie
Keyword(s):  
Hydrochloric Acid ◽  
Pore Size ◽  
Mesoporous Materials ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Mesoporous Structure ◽  
Ammonium Bromide ◽  
Pore Sizes ◽  
Silica Source ◽  
Cetyl Trimethyl Ammonium

The silica-based mesoporous materials were synthesized under normal atmospheric with Cetyl trimethyl ammonium bromide(CTAB) as surfactant, TEOS as silica source and hydrochloric acid as activator. The pore sizes distribution of mesoporous materials were adjusted by organic assistant reagent TMB(1,3,5-three toluol).The materials after and before TMB addition were characterized through XRD and IR. The results showed that the materials have regular hexagonal mesoporous structure. The structure is more regular and pore size is more bigger after TMB added.

Synthesis, Characterization of Bimetallic V-Fe-SBA-15 and Its Catalytic Performance in the Hydroxylation of Phenol

2007 ◽  
Vol 7 (12) ◽  
pp. 4508-4514 ◽  
Author(s):  
Fei Gao ◽  
Yanhua Zhang ◽  
Chunling Wang ◽  
Cheng Wu ◽  
Yan Kong ◽  
...  
Keyword(s):  
Ph Value ◽  
High Surface ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Hydroxylation Of Phenol ◽  
Surface Areas ◽  
Hexagonal Arrangement ◽  
Ft Ir ◽  
Catalytic Performances

A series of V-Fe incorporated-SBA-15 has been synthesized by adjustment of the pH value of the gel mixtures and characterized by using XRD, N2-adsorption, ICP, FT-IR, Raman, and UV–vis techniques. Results indicated that all samples exhibited typical hexagonal arrangement of mesoporous structure with high surface areas and the heteroatoms were probably incorporated into the framework of SBA-15. Catalytic performances of the obtained materials were evaluated in the hydroxylation of phenol with H2O2, and the catalytic results revealed that the selectivity for catechol (CAT) and hydroquinone (HQ) could be controlled by adjusting the contents of V and Fe in the samples, and an appropriate nV/nFe mol ratio in SBA-15 could approach the optimal catalytic performance.

scholarly journals Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 710
Author(s):  
Linmeng Huo ◽  
Tian Wang ◽  
Keng Xuan ◽  
Lei Li ◽  
Yanfeng Pu ◽  
...  
Keyword(s):  
Dimethyl Carbonate ◽  
Lewis Acid Site ◽  
Catalytic Performance ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Good Catalytic Activity ◽  
Adsorption Desorption

The adsorption and activation of both CO2 and methanol are mainly affected by the distance of the Lewis acid site, Zr4+, and Lewis base, Zr4+/O2−, of the Zr-based catalysts. In this paper, Zr-incorporated SBA-15 (Zr-SBA-15) and Zr-grafted SBA-15 (Zr/SBA-15) catalysts were prepared with different Zr environments, and were analyzed with N2 adsorption–desorption isotherms, X-ray diffraction, UV-vis spectra, and XPS. It was proposed that Zr-SBA-15 catalyst with Si-O-Zr-OH and Zr-O-Si-OH structure exhibited non-adjacent sites between Zr4+ and Zr4+/O2−, while Zr/SBA-15 catalyst with Zr-O-Zr-OH structure showed neighboring sites between Zr4+ and Zr4+/O2−. Furthermore, the Zr/SBA-15 catalyst exhibited good catalytic activity, while no DMC was detected over the Zr-SBA-15 catalyst at the same reaction conditions. For combined in situ infrared and catalytic performance, it was indicated that the methanol and CO2 could be activated to form DMC, only when the Zr4+ and Zr4+/O2− sites existed and were adjacent to each other in the Zr-O-Zr-OH of Zr/SBA-15 catalyst.

Catalytic Synthesis of Dioctyl Phthalate over Al-MCM-41 Molecular Sieves

2011 ◽  
Vol 306-307 ◽  
pp. 1741-1746
Author(s):  
Hua Feng Zhou ◽  
Yong Jin Yang ◽  
Jin Son Zhang
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Hydrothermal Process ◽  
Analytical Techniques ◽  
Catalytic Performance ◽  
Dioctyl Phthalate ◽  
Catalytic Synthesis ◽  
Al Content ◽  
Good Catalytic Activity ◽  
Mcm 41

In this paper, mesoporous MCM-41 and Al-MCM-41(Si/Al =100, 70, 40, 10, 5) molecular sieves were synthesized by direct hydrothermal process and characterized by various analytical techniques. Their catalytic performance in the synthesis of dioctyl phthalate (DOP) was also studied. The results show that while keeping the mesostructure of Al-MCM-41(Si/Al=100, 70, 40), increasing Al content can increase the acidity and so forth effectively improve the catalytic activity. But too much aluminum incorporation can destroy the structure of Al-MCM-41(Si/Al=10). The Al-MCM-41 molecular sieves with proper Si/Al ratios have good catalytic activity and stability in DOP synthesis. When Al-MCM-41(40) was used as the catalyst, A high PA conversion of 98.45% can be reached in 4 h. After being reused for five times, Al-MCM-41(40) still remains good catalytic activity.

Pd/ZrO2: An Efficient Catalyst for Liquid Phase Oxidation of Toluene in Solvent Free Conditions

2017 ◽  
Vol 15 (2) ◽  
Author(s):  
Mohsin Siddique ◽  
Muhammad Saeed ◽  
Mohammad Ilyas ◽  
Hussain Gulab
Keyword(s):  
Batch Reactor ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Solvent Free ◽  
Catalyst Loading ◽  
Similar Reaction ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Free Oxidation

Abstract 0.1 % Pd/ZrO2 was synthesized and characterized by various physicochemical techniques and was successfully used as catalyst for solvent free oxidation of toluene in the presence of molecular oxygen using batch reactor. The catalytic performance of Pd/ZrO2 was explored in terms of effect of catalyst loading, reaction time, temperature and partial pressure of oxygen on oxidation of toluene in solvent free conditions. Pd/ZrO2 was found as a stable catalyst under the reaction conditions. Used catalyst exhibited the same catalytic efficiency as fresh catalyst under similar reaction conditions. Reaction was taking place according to Langmuir-Hinshelwood type of mechanism.

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