Catalytic wet peroxide oxidation of maleic acid: Characterization of copper/micelle templated silica-3-aminopropyltrimethoxysilane and kinetics

Abstract

The study of catalysts enables the catalyst scientist to identify and understand the important steps such as active sites and stages in a catalysts’ lifetime. It is thus possible for scientists to design in more rational way, new and efficient catalysts. Therefore, the aim of this study was characterization of copper/micelle templated silica-3-aminopropyltrimethoxysilane (Cu/MTS-AMP) catalyst and study of kinetic parameters of maleic acid in catalytic wet peroxide oxidation. Scanning electron microscope and diffused reflectance infrared Fourier transform spectroscopy were used. SEM pictures of the Cu/ MTS-AMP - pyridine-2-carboxyaldehyde and Cu/ MTS-AMP - 2-hydroxy-1-naphthaldehyde samples show visible differences. The 2-hydroxy-1-naphthaldehyde showed clearly the principal band compared to pyridine-2-carboxyaldehyde. This led to conclusion that the 2-hydroxy-1-naphthaldehyde ligand might be a better choice compared to the pyridine-2-carboxyaldehyde to be used in the preparation of heterogeneous catalysts. However, the catalysts did not show differences in catalytic wet peroxide oxidation of maleic acid. The order of reaction was first order with respect to maleic acid, activation energy Ea, was, 67.052 kJ/mol and pre-exponential factor was 108 × 106 s-1. It was concluded that Cu/ MTS-AMP catalyst was effective for liquid phase oxidation of organic compounds and can be applied for catalytic wastewater treatment systems. Key words: Catalytic wet peroxide oxidation (CWPO), characterization, copper/micelle templated silica-3-aminopropyltrimethoxysilane (Cu/MTS-AMP), kinetics, wastewater treatment.