Selective catalytic reduction of nitrous oxide over Fe-ZSM-5: the effect of ion-exchange level

✍ Scribed by Kenji Yamada; Satoshi Kondo; Kohichi Segawa

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 242 KB
• Volume: 35-36
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(99)00223-1

✦ Synopsis

The direct decomposition and selective reduction of nitrous oxide (N 2 O) over Fe-ZSM-5 have been investigated in the presence of oxygen, using propene (C 3 H 6 ) as reductant. The results are compared with those obtained over Cu-ZSM-5, which is known to possess very high activity for direct decomposition. When propene was added as reductant, the activity of Fe-ZSM-5 dramatically increased compared with the direct decomposition of N 2 O, whereas Cu-ZSM-5 was strongly deactivated. Some Fe-ZSM-5 catalysts having different ion-exchange levels have been prepared in order to investigate the effect of Fe ion on the selective reduction of N 2 O. The conversion of N 2 O to N 2 and the reactivity of absorbed C 3 H 6 with N 2 O were increased with increased ion-exchange level. The activity over Fe-ZSM-5 (ion-exchange level=81%) after calcination at 1073 K was found to be slightly higher than that at 773 K. Moreover, the observation of FT-IR spectroscopy after adsorption of C 3 H 6 or pyridine on the catalyst showed that most of the Brønsted sites after calcination at 1073 K had disappeared. The results suggest that this reaction occurs mainly on Lewis acidic sites generated after the ion-exchange.