Development of Reusable Nanoporous Solid Catalysts for Liquid Phase Oxidation of Organic Compounds

Project Number
RI 5/12 WKL

Project Duration
March 2013 - March 2017

Status
In-Progress (Extended)

Abstract
Oxidation reactions are of paramount importance in natural processes, and are key transformations in synthetic chemistry by creating functional groups in organic molecules or modifying existing functional groups. Numerous methods and reagents have been developed for performing oxidation reactions on organic compounds. However, many existing methods have serious drawbacks. Particularly, numerous industrial processes involve oxidation of organic compounds in the liquid phase are carried out with homogeneous catalysts and excessive amount of inorganic oxidants. Such oxidation reactions not only non-environmentally benign, but also not economically favourable because toxic effluents will be generated as by-products, and consequently require extensive clean-up and separation processes. These problems can be solved if heterogeneous solid catalysts are to be used, due to their ease of separation, the lack of corrosion problems, and possible reusability of the catalysts. In addition, hydrogen peroxide (H2O2) is an ideal oxidant that can be used in heterogeneous catalytic systems, because the atom efficiency is excellent and water will be the sole by-product. Despite the heterogeneous catalysts can be reused for subsequent cycles of reaction, the catalytic activities usually decrease dramatically due to deactivation of the catalysts. Hence development of reusable heterogeneous solid catalysts (that can retain their catalytic activity in subsequent cycles of reaction) is currently one of the major challenges to be solved. The goal of this project is to develop reusable heterogeneous catalyst for liquid phase oxidation of organic compounds based on metal-containing nanoporous solids. Many of the heterogeneous solid catalysts that have been developed so far are based on noble and rare metals. Our preliminary study has shown that tin-containing solid catalyst can be used for three subsequent cycle of oxidation reaction without significant loss of activity. Therefore, the possibility of using inexpensive and more sustainable metals such as tin (Sn) and copper (Cu) in the preparation of reusable solid catalysts will be explored in this project. Correlation between the physicochemical properties of various porous solids prepared and their catalytic properties in the oxidation of various organic compounds (alcohols and alkenes) using aqueous peroxide as oxidant is to be studied. The nanoporous solids with novel physicochemical properties, such as possessing high surface area (> 300 m2/g), high thermal stability and well-defined pore structure, are expected to bring a large improvement in the catalytic activity and selectivity, with minimal waste generated. Last but not least, causes of catalyst deactivation will be verified and overcome. the possibility of using inexpensive and more sustainable metals such as tin (Sn) and copper (Cu) in the preparation of reusable solid catalysts will be explored in this project. Correlation between the physicochemical properties of various porous solids prepared and their catalytic properties in the oxidation of various organic compounds (alcohols and alkenes) using aqueous peroxide as oxidant is to be studied. The nanoporous solids with novel physicochemical properties, such as possessing high surface area (> 300 m2/g), high thermal stability and well-defined pore structure, are expected to bring a large improvement in the catalytic activity and selectivity, with minimal waste generated. Last but not least, causes of catalyst deactivation will be verified and overcome.

Funding Source
NIE

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