The Role of Ti and Lewis Acidity in Manganese Oxide Octahedral Molecular Sieves Impregnated with Titanium in Oxidation Reactions

Bulletin of Chemical Reaction Engineering & Catalysis

Hadi Nur¹  Sheela Chandren²  Halimaton Hamdan²  Fitri Hayati² 

[1] (SCOPUS h-index: 14);Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor;

关键词: Titanium-impregnated manganese oxide molecular sieves;    oxidation;    Lewis acidity;    framework and non-framework Ti;   

DOI  :  10.9767/bcrec.9.1.5603.28-38

来源: DOAJ

【 摘 要 】

Octahedral manganese oxide molecular sieves (OMS-2) was prepared by precipitation method and modified by impregnation of titanium with different titanium/manganese (Ti/Mn) ratio. It was also discovered that Ti/Mn ratio of less than 0.5 still retains the original pure cryptomelane structure of OMS-2. However, for sample with Ti/Mn ratio of more than 0.5, some rutile phases of titania (TiO2) can be detected together with the cryptomelane phase. Lewis acid sites were also observed in the titanium modified OMS-2 (Ti-OMS-2). Ti-OMS-2 was then used as catalysts for the oxidation of cyclohexane, cyclohexene and styrene, where Ti-OMS-2 with Ti/Mn ratio of 0.67 was most active in all three of the oxidation reactions as compared to TiO2 and OMS-2. The results suggest that both titanium sites in framework and non-framework and the Lewis acidity created by the impregnation of Ti, increased the activity of OMS-2 in oxidation reactions. © 2014 BCREC UNDIP. All rights reserved

Received: 18th October 2013; Revised: 4th January 2014; Accepted: 4th January 2014

[How to Cite: Hayati, F., Chandren, S., Hamdan, H., Nur, H. (2014). The Role of Ti and Lewis Acidity in Manganese Oxide Octahedral Molecular Sieves Impregnated with Titanium in Oxidation Reactions. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1): 28-38. (doi:10.9767/bcrec.9.1.5603.28-38)]

[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5603.28-38 ]

 

【 授权许可】

Unknown