Photocatalytic conversion of NOx on AgCl/Al2O3 catalyst

The rate of NO conversion under UV illumination was evaluated over Ag/Al2O3 and AgCl/Al2O3 catalysts at room temperature. The AgCl/Al2O3 catalyst is highly active for the conversion of NOx. The conversion is enhanced in the presence of O-2 and further enhanced when oxygen coexists with hydrocarbons. Diffuse reflectance spectra of AgCl/Al2O3 and Ag/Al2O3 show an absorption band at similar to 250 nm, and a weak and broad band at similar to 230 nm, respectively. The high photocatalytic NOx conversion is achieved over the AgCl/Al2O3 catalyst-The conversion level of NOx is maintained above 60% over 5 h in the presence of O-2 and hydrocarbons under UV-irradiation. The absorption band at similar to 250 nm is ascribed to the band gap energy of crystallized AgCl particles on Al2O3. These results suggest that high photocatalytic NOx conversion proceeds on crystallized AgCl particles formed on Al2O3. (C) 1999 Elsevier Science B.V. All rights reserved.