Low temperature NOx removal from diesel exhaust by coupling ethylene glycol reforming with SCR

The reduction of NOx at 185 °C on Pd supported on Ti–pillared clay was studied using H2 and CO generated by reforming of ethylene glycol (EG) over a Na–Pt/γ-Al2O3 catalyst. It was found that for a stream containing 490 ppm NO, 5.8% O2, and 2.9% H2O, at a space velocity of ∼24,000 h−1, a stable NOx conversion of ∼55% was obtained when a stream of 1.36% EG was reformed under a condition that the EG conversion was complete and sufficient H2 and CO was produced. However, if the EG conversion was incomplete, the unreacted EG deactivated the deNOx catalyst, possibly by coking, that could not be regenerated by O2 treatment at reaction temperature. H2O suppressed the deNOx activity, but the effect was reversible and the activity could be recovered after removal of H2O. The deNOx activity was found to be higher on catalysts containing more highly dispersed Pd.