Improved performance of NOx reduction by H2 and CO over a Pd/Al2O3 catalyst at low temperatures under lean-burn conditions

Selective reduction of NOx by H2 and CO in excess O2 was studied using a Pd/Al2O3 catalyst. Incipient wetness impregnation into Al2O3 was done using PdCl2 as the metal precursor. The NOx conversion profile was maximal at 423 K (up to 95.2% for 250 ppm CO), at which temperature complete oxidation of H2 and CO occurred. There is a very strong synergic effect when both CO and H2 are simultaneously present in the feed. This catalyst has good selectivity towards N2 and has a window of operation going from 400 to 530 K. 2004 Elsevier B.V. All rights reserved.