http://www.cnr.it/ontology/cnr/individuo/prodotto/ID169360

FTIR of adsorbed species on Co-H-MOR and Co-Na-MOR under CH4 + NO + O2 stream: Catalytic activity and selectivity (Articolo in rivista)

Type

Articolo in rivista (Classe)
Prodotto della ricerca (Classe)

Label

FTIR of adsorbed species on Co-H-MOR and Co-Na-MOR under CH4 + NO + O2 stream: Catalytic activity and selectivity (Articolo in rivista) (literal)

Anno

2010-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1016/j.cattod.2010.01.004 (literal)

Alternative label

Pietrogiacomi D.; Campa M.C.; Indovina V. (2010)
FTIR of adsorbed species on Co-H-MOR and Co-Na-MOR under CH4 + NO + O2 stream: Catalytic activity and selectivity
in Catalysis Today; Elsevier BV, Amsterdam (Paesi Bassi)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Pietrogiacomi D.; Campa M.C.; Indovina V. (literal)

Pagina inizio

192 (literal)

Pagina fine

198 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://www.sciencedirect.com/science/article/pii/S0920586110000052 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

155 (literal)

Rivista

Catalysis Today (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#note

fasc. (3-4). Elsevier. (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

7 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo

3-4 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

a) Dipartimento di Chimica, \"Sapienza\" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy b) Sezione \"Materiali Inorganici e Catalisi Eterogenea\" dell'Istituto ISC (CNR) c/o Dipartimento di Chimica, \"Sapienza\" Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy (literal)

Titolo

FTIR of adsorbed species on Co-H-MOR and Co-Na-MOR under CH4 + NO + O2 stream: Catalytic activity and selectivity (literal)

Abstract

The selective catalytic reduction (SCR) of NO with CH4 in the presence of excess O2 was studied on Co-H-MOR and Co-Na-MOR prepared from H-MOR and Na-MOR, respectively, by cobalt ion-exchange and containing nearly the same Co percentage (66 and 61%) but very different H+ and Na+ amounts. Catalyst characterization was performed using NO as a probe at room temperature, and by means of in situ FTIR study at the reaction temperature (573-773 K) in the presence of flowing reactant mixtures of various compositions ([CH4] = 0 or 4000 ppm, [NO] = 0 or 4000 ppm, [O2] = 0 or 20,000 ppm, balance He). In one selected case, the operando FTIR-GC methodology was used. The activity for SCR was nearly the same on the two catalysts, whereas the selectivity was higher on Co-H-MOR than on Co-Na-MOR. NO adsorption at room temperature did not show major differences in the type of cobalt species present on the two samples, being nearly all cobalt present as isolated Co2+ with two coordinative vacancies. The in situ FTIR characterization under reaction conditions identifies Co2+-mononitrosyls. We suggest that this mononitrosyl is a key species for the catalytic activity in the SCR reaction. Conversely, the in situ FTIR study under reaction conditions evidenced major differences between the surface nitrogen-oxo species (NOy, oxidation number of nitrogen >2) formed on the two samples, specifically NO+ on Co-H-MOR-66, and Co2+-monodentate nitrates on Co-Na-MOR-61. We suggest that Co2+-monodentate nitrate favors the CH4 combustion, accounting for the finding that the SSCR selectivity of Co-Na-MOR-61 is lower than that of Co-H-MOR-66. (literal)

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