Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The reduction of V₂O₅/Al₂O₃ (15 mass % V₂O₅) and V₂O₅ by ammonia, hydrogen, and a NO + NH₃ mixture, and the oxidation of pre-reduced catalysts by oxygen and nitrogen oxide have been investigated. For both catalysts, the reduction rate increases in the sequence H₂ < NH₃ < NO + NH₃. From the character of the temperature and concentration dependences of the oxidation state of vanadium, it has been concluded that in the temperature range 100 to 175 °C the catalysts are reduced by the NO + NH₃ mixture within the surface layer only. The reaction of this mixture with oxidized surface of vanadium catalyst is of the same order with respect to NO and NH₃ concentrations.