Sulfation: a simple method to enhance the catalytic activity of TS-1 in epoxidation of 1-octene with aqueous hydrogen peroxide

2004 ◽  
Vol 5 (12) ◽  
pp. 725-728 ◽  
Author(s):  
Hadi Nur ◽  
Didik Prasetyoko ◽  
Zainab Ramli ◽  
Salasiah Endud
2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Mukhamad Nurhadi ◽  
Jon Efendi ◽  
Lee Siew Ling ◽  
Teuku Meurah Indra Mahlia ◽  
Ho Chin Siong ◽  
...  

Titanium dioxide supported sulfonated low rank coal catalyst possesses high catalytic activity in liquid phase oxidation of styrene with aqueous hydrogen peroxide at room temperature. The catalysts were prepared by sulfonation with concentrated sulfuric acid and impregnation of titanium dioxide (500-2500 µmol). The effect of titanium dioxide impregnation and calcinations on the catalysts were studied by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, BET surface area, field emission scanning electron microscopy and hydrophobicity measurement. The catalytic activity of the catalysts in the oxidation of styrene by aqueous H2O2 without calcination increased when the amount of titanium dioxide increased. Meanwhile, the catalytic activity of the catalyst calcined at 500oC for 2 h was lower than before calcination. It is suggested that the agglomeration of titanium dioxide and hydrophobicity play important role in the catalytic activity of titanium dioxide-supported sulfonated low rank coal in the oxidation of styrene with aqueous H2O2. 


Author(s):  
Mukhamad Nurhadi

<p>The modified coal char from low-rank coal by sulfonation, titanium impregnation and followed by alkyl silylation possesses high catalytic activity in styrene oxidation. The surface of coal char was undergone several steps as such: modification using concentrated sulfuric acid in the sulfonation process, impregnation of 500 mmol titanium(IV) isopropoxide and followed by alkyl silylation of n-octadecyltriclorosilane (OTS). The catalysts were characterized by X-ray diffraction (XRD), IR spectroscopy, nitrogen adsorption, and hydrophobicity. The catalytic activity of the catalysts has been examined in the liquid phase styrene oxidation by using aqueous hydrogen peroxide as oxidant. The catalytic study showed the alkyl silylation could enhance the catalytic activity of Ti-SO<sub>3</sub>H/CC-600(2.0). High catalytic activity and reusability of the o-Ti-SO<sub>3</sub>H/CC-600(2.0) were related to the modification of local environment of titanium active sites and the enhancement the hydrophobicity of catalyst particle by alkyl silylation. Copyright © 2017 BCREC GROUP. All rights reserved</p><p><em>Received: 24<sup>th</sup> May 2016; Revised: 11<sup>st</sup> October 2016; Accepted: 18<sup>th</sup> October 2016</em></p><p><strong>How to Cite:</strong> Nurhadi, M. (2017). Modification of Coal Char-loaded TiO<sub>2</sub> by Sulfonation and Alkylsilylation to Enhance Catalytic Activity in Styrene Oxidation with Hydrogen Peroxide as Oxidant. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 12 (1): 55-61 (doi:10.9767/bcrec.12.1.501.55-61)</p><p><strong>Permalink/DOI</strong>: http://dx.doi.org/10.9767/bcrec.12.1.501.55-61</p><p> </p>


2009 ◽  
Vol 52 (6-7) ◽  
pp. 693-698 ◽  
Author(s):  
Kenji Wada ◽  
Kazuhiko Hirabayashi ◽  
Naoki Watanabe ◽  
Shingo Yamamoto ◽  
Teruyuki Kondo ◽  
...  

1979 ◽  
Vol 44 (4) ◽  
pp. 1015-1022 ◽  
Author(s):  
Viliam Múčka

The catalytic properties of two-component catalyst nickel oxide-cadmium oxide with the proportions of the components covering the whole composition region 0-100% were examined by studying the decomposition of hydrogen peroxide in aqueous solution on it. In the range 0-25 mol.% CdO, cadmium oxide is found to affect infavourably the ability of nickel oxide to chemisorb oxygen. The amount of the chemisorbed oxygen increases several times on gamma irradiation of the samples. The effect of cadmium oxide on the catalytic activity of the system shows up in fresh samples only indirectly via the changed amount of the oxygen chemisorbed. In older samples the initial catalytic activity of the system is changed, which can be explained based on the concept of bivalent catalytic centres in terms of the co-action of the catalytic centres of the two oxides, which are in equilibrium. The irradiation of the system under study speeds up the processes leading to the establishing of this equilibrium which is thermally very stable, and results in a substantial increase of the catalytic activity of the samples investigated.


1988 ◽  
Vol 53 (8) ◽  
pp. 1636-1646 ◽  
Author(s):  
Viliam Múčka ◽  
Kamil Lang

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.


Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 283
Author(s):  
Oxana Kholdeeva ◽  
Nataliya Maksimchuk

In recent years, metal–organic frameworks (MOFs) have received increasing attention as selective oxidation catalysts and supports for their construction. In this short review paper, we survey recent findings concerning use of MOFs in heterogeneous liquid-phase selective oxidation catalysis with the green oxidant–aqueous hydrogen peroxide. MOFs having outstanding thermal and chemical stability, such as Cr(III)-based MIL-101, Ti(IV)-based MIL-125, Zr(IV)-based UiO-66(67), Zn(II)-based ZIF-8, and some others, will be in the main focus of this work. The effects of the metal nature and MOF structure on catalytic activity and oxidation selectivity are analyzed and the mechanisms of hydrogen peroxide activation are discussed. In some cases, we also make an attempt to analyze relationships between liquid-phase adsorption properties of MOFs and peculiarities of their catalytic performance. Attempts of using MOFs as supports for construction of single-site catalysts through their modification with heterometals will be also addressed in relation to the use of such catalysts for activation of H2O2. Special attention is given to the critical issues of catalyst stability and reusability. The scope and limitations of MOF catalysts in H2O2-based selective oxidation are discussed.


Sign in / Sign up

Export Citation Format

Share Document