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
RESUMO -A decomposição de N 2 O é uma rota alternativa para reduzir a emissão desse gás em processos industriais. Essa rota catalítica se destaca pela simplicidade e baixo custo. Catalisadores CaWO 4 , CoWO 4 e Ca 0,5 Co 0,5 WO 4 foram preparados pelo método de co-precipitação, caracterizados por DRX e MEV e avaliados na decomposição de N 2 O. Os resultados mostraram a formação de estruturas com morfologia irregular do tipo wolframita para o CoWO 4 e scheelita para o CaWO 4 . O catalisador Ca 0,5 Co 0,5 WO 4 apresentou os picos de menor intensidade referentes aos tungstatos precursores. Os tungstatos foram ativos para a decomposição de N 2 O, seguindo a ordem de atividade CoWO 4 > CaWO 4 > Ca 0,5 Co 0,5 WO 4 , mostrando potencial aplicação na catálise heterogênea.
Estudo da decomposição de óxido nitroso sobre tungstatos de cálcio e/ou cobalto Study of decomposition of nitrous oxide on calcium and / or cobalt tungstates
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.