Combined kinetic and potentiometric measurements of the reduction of nitrogen monoxide on vanadia titania catalysts

The selective catalytic reduction of nitrogen oxide by ammonia on vanadia t itania catalysts has been studied by combined kinetic and potentiometric (S EP) measurements using yttria stabilized zirconia. At temperatures between 300 and 390 degrees C the concentration of NO and NH, varied from 100 to 20 00 ppm. The influence of oxygen and water vapour were equally studied in th e domain 0 < x(O2) < 0.08 and 0 < x(H2O) < 0,05. The results indicate that the highest catalytic activity of the catalyst is related to the presence o f V5+ ions but there is no correlation between the selectivity of the N-2 f ormation and the oxidation state of the catalyst. The combined kinetic and potentiometric measurements confirm the often proposed mechanism of oxygen transfer via the catalyst. (C) 1999 Elsevier Science S.A. All rights reserv ed.