Untitled

Lezcano, Marta; Kovalchuk, Vladimir I.; d’Itri, Julie L.

doi:10.1023/a:1004813115825

Cited by 39 publications

(44 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several studies have outlined that NO 2 in particular plays an important role in the reduction of NO x to N 2 . It has been reported that NO is oxidized to NO 2 with oxygen and then the resulting NO 2 reacts with hydrocarbons to form an active intermediate [53,[57][58][59]. In our case, NO adsorption shows nitrosyl complexes as primary compounds formed in the most active Fe 2+ ZP, NO + in Fe 3+ ZP, and N 2 O in the least active ZP.…”

Section: Discussionsupporting

confidence: 48%

See 1 more Smart Citation

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

et al. 2019

View full text Add to dashboard Cite

Natural purified mordenite from Palmarito de Cauto (ZP) deposit, Cuba, was subjected to a hydrothermal ion exchange process in acid medium with Fe2+ or Fe3+ salts (Fe2+ZP and Fe3+ZP). The set of samples was characterized regarding their textural properties, morphology, and crystallinity, and tested in the NO reduction with CO/C3H6. Infrared spectroscopy coupled with NO as a probe molecule was used to give a qualitative description of the Fe species’ nature and distribution. The exchange process caused an increase in the iron loading of the samples and a redistribution, resulting in more dispersed Fe2+ and Fe3+ species. When contacted with the NO probe, Fe2+ZP showed the highest intensity of nitrosyl bands, assigned to NO adducts on isolated/highly dispersed Fe2+/Fe3+ extra-framework sites and FexOy clusters. This sample is also characterized by the highest NO sorption capacity and activity in NO reduction. Fe3+ZP showed a higher intensity of nitrosonium (NO+) species, without a correlation to NO storage and conversion, pointing to the reactivity of small FexOy aggregates in providing oxygen atoms for the NO to NO+ reaction. The same sites are proposed to be responsible for the higher production of CO2 observed on this sample, and thus to be detrimental to the activity in NO SCR.

show abstract

Section: Discussionsupporting

confidence: 48%

“…A similar trend with a lower intensity is observed on sample Fe 3+ ZP (curves E). Bands in this spectral region have often been observed on synthetic Fe-zeolites, and are mainly ascribed to highly dispersed Fe 2+ and Fe 3+ sites [19,44,45,52,53].…”

Section: Fe 2+ Zp and Fe 3+ Zp Samplesmentioning

confidence: 89%

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The two strong bands at 1870-1890 cm -1 were observed earlier for different Fe-ZSM-5 samples. 12,24,25 However, two strong bands at 1856 and 1882 cm - 1 23,30 or only one band at around 1880 cm -1 were also reported. 3,22,23,[31][32][33] The differences could be due to different NO partial pressures, time-on-stream, temperature, conditions of catalysts synthesis, activation, and pretreatments.…”

Section: No Adsorption On the Surface Iron Sitesmentioning

confidence: 99%

Formation of the Surface NO during N₂O Interaction at Low Temperature with Iron-Containing ZSM-5

2005

View full text Add to dashboard Cite

Interaction of N2O at low temperatures (473-603 K) with Fe-ZSM-5 zeolites (Fe, 0.01-2.1 wt %) activated by steaming and/or thermal treatment in He at 1323 K was studied by the transient response method and temperature-programmed desorption (TPD). Diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) of NO adsorbed at room temperature as a probe molecule indicated heterogeneity of surface Fe(II) sites. The most intensive bands were found at 1878 and 1891 cm(-1), characteristic of two types mononitrosyl species assigned to Fe2+(NO) involved in bi- and oligonuclear species. Fast loading of atomic oxygen from N2O on the surface and slower formation of adsorbed NO species were observed. The initial rate of adsorbed NO formation was linearly dependent on the concentration of active Fe sites assigned to bi- and oligonuclear species, evolving oxygen in the TPD at around 630-670 K. The maximal coverage of a zeolite surface by NO was estimated from the TPD of NO at approximately 700 K. This allowed the simulation of the dynamics of the adsorbed NO formation at 523 K, which was consistent with the experiments. The adsorbed NO facilitated the atomic oxygen recombination/desorption, the rate determining step during N2O decomposition to O2 and N2, taking place at temperatures > or =563 K.

show abstract

“…4a). The band at 1880 cm À1 has been assigned to mono-nitrosylic species associated with Fe sites in the 2+ state (Fe 2+ -NO) [20]. In addition to this band, a shoulder at 1815 cm À1 is observed.…”

Section: Epr Spectroscopymentioning

confidence: 99%

Characterization and catalytic investigation of Fe-ZSM5 for urea-SCR

et al. 2007

View full text Add to dashboard Cite

Untitled

Cited by 39 publications

References 48 publications

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

Formation of the Surface NO during N₂O Interaction at Low Temperature with Iron-Containing ZSM-5

Characterization and catalytic investigation of Fe-ZSM5 for urea-SCR

Contact Info

Product

Resources

About

Untitled

Cited by 39 publications

References 48 publications

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts

Formation of the Surface NO during N2O Interaction at Low Temperature with Iron-Containing ZSM-5

Characterization and catalytic investigation of Fe-ZSM5 for urea-SCR

Contact Info

Product

Resources

About

Formation of the Surface NO during N₂O Interaction at Low Temperature with Iron-Containing ZSM-5