LEAN-DENO(X) TITANIA BASED MONOLITHIC CATALYSTS

The activity of titania based copper and platinum monolithic catalysts in the reduction of nitrogen oxides was studied with exhaust gases fr om a Diesel engine injecting fuel as reductant. Combining both catalys ts, a two-stage system was designed, studying the influence of the cop per catalysts composition on its performance with synthetic gas mixtur es. The influence of reactants concentration and operating conditions was also investigated. Taking into account these results, a double-bed system with a cell density of 33 cell cm(-2) (210 c.p.s.i.) was prepa red. Linear velocity had a strong influence on the performance of the Pt catalyst and of the double-bed. Two NOx conversion maxima were obse rved with Pt/TiO2 at 225 degrees C and 350 degrees C operating at 6.6 m s(-1). Promising NOx conversions were achieved in the temperature ra nge 200-450 degrees C. (C) 1998 Elsevier Science B.V. All rights reser ved.