Improvement of Al2O3 on the multi-pollutant control performance of NOx and chlorobenzene in vanadia-based catalysts

We compared the influences of Al2O3 and SiO2 on a traditional V2O5-MoO3/TiO2 for the simultaneous removal of NOx and chlorobenzene (CB). The Al2O3 doping catalyst considerably broadens the active temperature window with higher NOx reduction and CB oxidation efficiencies than the SiO2 doping one and the V2O5-MoO3/TiO2. Furthermore, its resistance to SO2 was preserved and the quantities of polychlorinated byproducts also decreased. The increase in activity at low temperatures could be due to the promotion of vanadia reducibility via interactions between V2O5 and Al2O3. Moreover, the high temperature activity could be due to the additional surface acidities provided by Al2O3, in which the Lewis acid sites played the predominant role in both NH3 adsorptions and CB de-chlorination compared to the Brønsted acid sites. Finally, we proposed that Al2O3 is an effective addition for vanadia-based catalyst in NOx and CB simultaneous removal from stationary sources.