SBA-15에 擔持된 金屬觸媒에 의한 벤젠의 燃燒反應

Abstract

Catalytic combustion of benzene over metal oxides supported on SBA-15 has been investigated. The catalysts have been prepared by incipient wetness method, precipitation-deposition method and chelating method. These catalysts were characterized by XRD, BET, TEM, ESR, ICP and TPR in order to determine the nature of the metal oxide species supported on SBA-15. In addition, their catalytic activity on benzene combustion in the presence of oxygen was also examined along with the effect of the type of supports, metal oxide, pretreatment conditions, preparation method of catalysts and copper loading ratio and the following conclusions are drawn. 1. Calcined siliceous SBA-15 and CuO/SBA-15 materials samples displayed well-resolved pattern with a sharp peak at about 1.0o. It is clear that CuO loaded on the silica matrix drastically decreases the surface area and pore volume of the catalysts as expected for CuO incorporation. From the ESR results, the CuO dispersed on the SBA-15 acts as an active site of CuO/SBA-15 catalysts on the oxidative decomposition of benzene. 2. Among supported metal oxides, CuO supported on SBA-15 is found to have the highest activity for benzene oxidation. In addition, the copper oxide supported on SBA-15 gives the higher catalytic activity than copper oxide supported on MCM-41. The catalytic activity of SBA-15 supported metal oxides shows in the order; Cu>Mn>Fe>Ni. In addition, the catalysts prepared by chelating method shows the highest activity among the catalysts prepared by different method. 3. The catalytic activity gradually increases with an increase of CuO loading and the calcination at high temperature gives a rise to sintering of copper oxide particles and the formation of large CuO particles or bulk copper oxide phase, resulting in the decrease of catalytic activity. 4. The metallic Cu is much more active than the copper oxides for the combustion of benzene, resulting from generating active metallic copper particles with reduction treatment. 5. The catalytic activity increases with an increase of oxygen concentration but the concentration of benzene shows no effect on the benzene conversion. The catalytic activity increases with an decrease of space velocity.