- Tytuł:
- Selective catalytic reduction of NO,sub>x with ammonia (NH3-SCR) over transition metal-based catalysts -influence of the catalysts support
- Autorzy:
-
Szymaszek, Agnieszka
Samojeden, Bogdan
Motak, Monika - Powiązania:
- https://bibliotekanauki.pl/articles/109757.pdf
- Data publikacji:
- 2019
- Wydawca:
- Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
- Tematy:
-
NH3-SCR
NOx
clinoptilolite
layered clays
iron - Opis:
- Natural layered clays (bentonite and vermiculite) and natural zeolite (clinoptilolite) were tested and compared as the supports of the catalysts forselective catalytic reduction withammonia (NH3-SCR). The raw materials were modified in order to improve their catalytic properties. Layered clays were treated with HNO3 and intercalated with Al2O3 pillars to enhance their acidity, porosity and specific surface area. Clinoptilolite was ion-exchanged with NH4NO3 in order to increase the content of Brönsted acid sites, indispensablefor NH3 adsorptionduring the reaction. Subsequently, iron as an active phase was deposited on the modified supports by various methods, including incipient wetness impregnation, ion-exchange and co-precipitation. The efficiency of these methods was compared as NOx conversionobtained for each material. XRD analysis indicated that the initial modifications affected the structure of the raw aluminosilicates. FT-IR measurement confirmed the presence of characteristic Si-O and Al-O bonds and H2O molecules that occurnaturally in the materials. UV-Vis spectroscopy results indicated that different types of Fe species were deposited on the catalysts surface and theirform strongly depends on the type of the support. NH3-SCR catalytic tests showedthat all of the analyzed materials exhibitsatisfactory level of NO conversion and negligible concentration of by-product (N2O) in the exhaust gas. The highest catalytic activity (ca. 50% at 170°C and over 95% above 250°C) was obtained for Fe-Bent. The lowest concentration of N2O in the flue gas (less than 5 ppm in the whole temperature range) was observed for Fe-Clin.
- Źródło:
-
Physicochemical Problems of Mineral Processing; 2019, 55, 6; 1429-1441
1643-1049
2084-4735 - Pojawia się w:
- Physicochemical Problems of Mineral Processing
- Dostawca treści:
- Biblioteka Nauki
Artykuł