Properties of Iron-Modified-by-Silver Supported on Mordenite as Catalysts for NOx Reduction
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Catalysts
ISSN: 2073-4344
|
| Output data |
Year: 2020,
Volume: 10,
Number: 10,
Article number
: 1156,
Pages count
: 17
DOI:
10.3390/catal10101156
|
| Tags |
iron; silver; mordenite; bimetallic; deposition order; ion exchange; de-NOx |
| Authors |
Sánchez-López Perla
1
,
Kotolevich Yulia
1
,
Khramov Evgeny
2
,
Chowdari Ramesh Kumar
1
,
Estrada Miguel Angel
1
,
Berlier Gloria
3
,
Zubavichus Yan
4
,
Fuentes Sergio
1
,
Petranovskii Vitalii
1
,
Chávez-Rivas Fernando
5
|
| Affiliations |
| 1 |
Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada 22860, Mexico
|
| 2 |
National Research Center “Kurchatov Institute”, Moscow 123182, Russia
|
| 3 |
Dipartimento di Chimica and NIS Centre, Università di Torino, Via P. Giuria 7, 10125 Torino, Italy
|
| 4 |
Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
|
| 5 |
Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, México City 07738, Mexico
|
|
Funding (3)
|
1
|
Ministry of Science and Higher Education of the Russian Federation
|
0239-2019-0003
|
|
2
|
National Council of Science and Technology
|
117373
|
|
3
|
National Polytechnic Institute
|
|
A series of mono and bimetallic catalysts based on a Fe-Ag mixture deposited on mordenite was prepared by ion-exchange and evaluated in the catalytic activity test of the de-NOx reaction in the presence of CO/C3H6. The activity results showed that the most active samples were the Fe-containing ones, and at high temperatures, a co-promoter e ect of Ag on the activity of Fe catalysts was also observed. The influence of the order of cation deposition on catalysts formation and their physicochemical properties was studied by FTIR (Fourier Transform Infrared Spectroscopy)
of adsorbed NO, XANES (X-ray Absorption Near-Edge Structure), and EXAFS (Extended X-ray Absorption Fine Structure) and discussed in terms of the state of iron. Results of Fe K-edge XANES oscillations showed that, in FeMOR catalysts, iron was present in a disordered state as Fe3+ and Fe2+. In FeAgMOR, the prevailing species was Fe3+, while in the AgFeMOR catalyst, the state of iron was intermediate or mixed between FeMOR and FeAgMOR. The Fe K-edge EXAFS results were characteristic of a disordered phase, the first coordination sphere being asymmetric with two di erent
Fe-O distances. In FeAgMOR and AgFeMOR, coordination of Fe-O was similar to Fe2O3 with a few amount of Fe2+ species. We may conclude that, in the bimetallic FeAgMOR and AgFeMOR samples, a certain amount of tetrahedral Al3+ ions in the mordenite framework is replaced by Fe3+ ions, confirming the previous reports that these species are active sites for the de-NOx reaction. Based on the thermodynamic analysis and experimental data, also, it was confirmed that the order of deposition of the components influenced the mechanism of active sites’ formation during the two
steps ion-exchange synthesis.