Surface and catalytic properties of CuO doped with MgO and Ag2O

The effects of doping of CuO solid with MgO (0.4-1.5 mol%) and Ag2O (0.2-0. 75 mol%) on its surface and catalytic properties were investigated. The res ults obtained revealed that MgO doping of CuO conducted at 300-700 degreesC resulted in an increase of 18% for S-BET while Ag2O treatment exerted a de crease of 19% for S-BET Of the doped adsorbents. The doping of CuO either w ith MgO or Ag2O conducted at 300-700 degreesC effected an increase in its c atalytic activity towards H2O2 decomposition to an extent proportional to t he concentration of the dopant employed. The addition of 1.5 mol% MgO follo wed by precalcination at 300-700 degreesC resulted in an increase of 46, 87 and 50% in the value of the reaction rate constant measured at 30 degreesC (k(30 degreesC)) over the solids precalcined at 300, 500 and 700 degreesC, respectively. The treatment of CuO with 0.75 mol% Ag2O carried out at 300- 700 degreesC exerted an increase of 285, 925 and 1170% in the value of k(30 degreesC) for the reaction taking place over the treated solids calcined a t 300, 500 and 700 degreesC, respectively. The measurement of activation en ergy of the catalytic reaction for pure and variously doped solids revealed that the doping process did not modify the energetic nature of the active sites involved in the catalysed reaction but increase their concentration. (C) 2001 Elsevier Science B.V. All rights reserved.