An efficient SnyMn1-yOx composite oxide catalyst for catalytic combustion of it vinyl chloride emissions

A series of SnyMn1-yOx composite oxide catalysts with different Sn/Mn molar ratios (y = 1.0, 0.8, 0.6, 0.3 and 0) were prepared by a co-precipitation method. The catalysts were investigated for the catalytic combustion of vinyl chloride (VC), which is a typical chlorinated volatile organic compound (CVOC). It is found that the existence of Sn-Mn-O solid solution structure over Sn(y)Mn(1-y)O(x )catalysts can increase the specific surface area and tune the valence state of Mn and the surface properties. As a result, the redox property and the ability of adsorbing oxygen species of SnyMn1-yOx catalysts are enhanced. Meanwhile, more weak and medium acid sites are present on the catalyst surface. Under the synergetic effects of these above-mentioned factors, the catalytic activity of SnyMn1-yOx catalyst for VC oxidation is significantly improved compared with pure SnOx and MnOx catalysts. Moreover, the Sn/Mn molar ratio significantly affects the catalytic activity of SnyMn1-yOx catalysts, among which Sn0.6Mn0.4Ox catalyst possesses the best catalytic activity and excellent resistance to Cl poisoning and water-resisting ability. It can retain VC conversion of 100% without any chlorinated byproducts for 100 h at the reaction temperature of 340 degrees C.