Influence of co-fed gases (O2, CO2, CH4, and H2O) on the N2O decomposition over (Co, Fe)-ZSM-5 and (Co, Fe)-BETA catalysts

Abstract

The influence of co-fed gases (O 2 , CO 2 , CH 4 , and H 2 O) on the N 2 O decomposition over (Co or Fe)-BETA and (Co, Fe)-ZSM-5 catalysts prepared by ion exchange method was investigated. Co 2+ ions and oxo dinuclear Co species were identified in Co-ZSM-5 and Co-BETA catalysts. Isolated and oligomeric Fe 3+ species in cationic sites and Fe 2 O 3 particles were found on surface of the Fe-ZSM-5 and Fe-BETA catalysts. Cobalt catalysts were more actives than iron catalysts for the direct decomposition of N 2 O. Conversion of N 2 O over Fe-BETA and Fe-ZSM-5 was remained stable when co-fed O 2 , CO 2 , and CH 4 , but decreases with water vapor. However, Co-BETA and Co-ZSM-5 showed much larger reaction rate for N 2 O decomposition and were very stable when co-fed O 2 , CO 2 , CH 4 , and especially H 2 O. The results showed that the higher CH 4 consumption during N 2 O reaction over Co-BETA and Co-ZSM-5 was due to CH 4 combustion. Keywords N 2 O decomposition • Co-fed gases • Iron species • Cobalt species • ZSM-5 zeolite • BETA zeolite

Density Functional Theory Study of Mechanism of Reduction of N2O by CO over Fe-ZSM-5 Zeolites

“…This depletes ozone, causing the ozone hole problem [5,6]. The global warming potential of N 2 O per molecule is 300 and 21 times higher than those of carbon dioxide (CO 2 ) and methane (CH 4 ), respectively [7,8].…”