Mechanistic aspects involved in the formation of N2 and
of N2O during the reduction of gas-phase NO and of NO
x
stored over a model PtBa/Al2O3 NSR catalyst are investigated using unlabeled ammonia and
labeled NO. The reduction of the stored NO
x
species (labeled nitrites and nitrates) with NH3 leads
to the selective formation of N2 as a major product and
of small amounts of nitrous oxide. Based on the nitrogen isotopic
distribution, it appears that N2 formation occurs primarily
through the statistical coupling of N-atoms formed by dissociation
of NO
x
- and NH3-related surface
intermediates, although an SCR-pathway (involving the coupling of
NH3- and NO-derived ad-species) is also likely to occur.
It appears as well that the formation of nitrous oxide involves either
the coupling of two adsorbed NO molecules or the recombination of
an adsorbed NO molecule with an adsorbed NH
x
fragment.
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.