Spectroscopic studies of MFI and USY zeolite layers over stainless steel 316L wire gauze meshes

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2020-04, Vol.230, p.118060, Article 118060
• Main Authors: Kuterasiński, Ł., Bodzioch, P., Dymek, K., Jędrzejczyk, R.J., Chlebda, D.K., Łojewska, J., Sitarz, M., Kurowski, G., Jeleń, P., Jodłowski, P.J.
• Format: Article
• Language: English
• Subjects: In situ hydrothermal synthesis; SCR deNOx; Spectroscopic characterisation; Structured catalysts; Zeolite
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2020.118060

The objective of our study was to develop and optimize the in situ synthesis of zeolitic thin coatings with USY (ultrastabilised form of faujasite) and MFI (Model Five) type structure on metallic structured catalysts supports using the hydrothermal method. Thus, obtained zeolitic materials were studied in terms of their prospective activity in selective catalytic reduction of nitrogen oxides (SCR of NOx) with ammonia. Optimization of the preparation method consisted of several steps including: the pretreatment of steel carrier to obtain an adhesive surface, hydrothermal synthesis of zeolites at different conditions and adjustment of the zeolite structure type (MFI vs. USY). As a result, uniform zeolitic layers were deposited on steel supports. Prepared structured supports were ion-exchanged with copper or cobalt precursors to obtain active catalysts and then characterised by various physicochemical methods with a particular reference to the in situ Fourier-Transform Infrared Spectroscopy (FTIR), Ultraviolet–Visible Diffusion Reflectance Spectroscopy (DRS-UV/VIS) and Raman spectroscopy. For CuUSY sample, slightly better catalytic properties are related to higher copper content. In the case of Co-samples, worse catalytic properties in comparison with Cu counterparts might imply from higher concentration of Brønsted acid sites, lower cobalt loading (thus concentration of Lewis acid sites) and the presence of cobalt cation significantly in oxide form (evidenced by Raman, DRS-UV/VIS spectroscopy and by in situ FT-IR sorption studies). [Display omitted] •In situ synthesis of MFI and Y/USY type zeolites on structured supports is presented.•Uniformly distributed zeolitic coatings highly adhere to steel support.•Cu and Co as an active phase are uniformly distributed over zeolite.•Cu and Co species are both in cationic and oxide form.•Cu exchanged zeolites indicate high conversion and selectivity in SCR deNOx.