Abstract
MoOx/CeO2 catalysts prepared by impregnation with (NH4)6H8Mo7O_(28) aqueous solution were applied for catalytic oxidation of 1,2-dichloroethane. MoOx exists on CeO2 fluorite as isolated (O=)2Mo(O-Ce)2, poly MoO4 and nano-particles, of which (O=)2Mo(O-Ce)2 presents high acidity and reducibility of Mo, and decreases the basicity of CeO2, leading to the formation of reactive intermediate during 1,2-dichloroethane adsorption. The activity of MoOx/CeO2 catalysts for 1,2-dichloroethane oxidation increases with acidity and surface oxygen from CeO2 domain. The catalyst with 2.6 Mo atom nm~(-2) presents the highest apparent activity with T_(90) of 280 °C in feed containing 1000/2000 ppm 1,2-dichloroethane at 60,000 h~(-1) space velocity. For chlorinated aromatic oxidation, similar high stable activity is observed. The ability of (O=)2Mo(O-Ce)2 for water dissociation promotes Cl removal, and thus, the chlorination is inhibited completely within experiment temperature. Mo~(6+)=0 of (O=)2Mo (O-Ce)2 is highly stable in wet feed, leading to high resistance of MoOx/CeO2 catalysts to water.
NSTL