Fe Speciation in Iron Modified Natural Zeolites as Sustainable Environmental Catalysts
| Autor: | Fernando Chávez Rivas, Vitalii Petranovskii, Beatriz Concepción-Rosabal, Inocente Rodríguez-Iznaga, Daria Tito Ferro, Gloria Berlier |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
HRTEM
Inorganic chemistry Infrared spectroscopy 02 engineering and technology lcsh:Chemical technology 010402 general chemistry 01 natural sciences Catalysis Mordenite lcsh:Chemistry chemistry.chemical_compound Crystallinity natural zeolite lcsh:TP1-1185 Reactivity (chemistry) Physical and Theoretical Chemistry NO reduction Ion exchange Chemistry Nitrosonium Iron exchange FTIR-NO Sorption 021001 nanoscience & nanotechnology 0104 chemical sciences Natural zeolite lcsh:QD1-999 mordenite 0210 nano-technology |
| Zdroj: | Catalysts Volume 9 Issue 10 Catalysts, Vol 9, Iss 10, p 866 (2019) |
| ISSN: | 2073-4344 |
| DOI: | 10.3390/catal9100866 |
| Popis: | 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&rsquo 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. |
| Databáze: | OpenAIRE |
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