Sintered metal fibers coated with transition metal oxides as structured catalysts for hydrogen peroxide decomposition
This study aimed at the development of active and stable structured catalyst for the decomposition of hydrogen peroxide under industrial conditions. Sintered metal fibers of stainless steel (SMFss) in the form of flat panels were surface coated by different catalytic metal oxides. The oxide coating has been carried out by incipient wetness impregnation of SMFss with suitable precursors followed by calcination in air at temperatures between 500 and 600 degrees C. The coating of SMFss renders a very thin homogeneous oxide layer of less than 1 mu m covering the individual fibers and ensures an optimal accessibility of the treated H2O2 solution to the catalytically active phase without any mass-transfer limitations. In the decomposition of hydrogen peroxide, the 5 wt.% MnOx/5 wt.% (Al2O3 + MgO)/SMFss was found to be the most active and stable catalyst in a range of pH = 4-7 at 25 degrees C exhibiting a significant first order rate constant of 5.2 min(-1) at pH 7. The same catalyst was tested in the back end of the epoxidation of soybean oil process demonstrating its suitability for industrial application. (c) 2013 Elsevier B.V. All rights reserved.