Eco-friendly catalysts have been obtained by functionalizing hydroxyapatite (HAP) with iron (Fe/HAP), according to three preparative methods (flash ionic exchange, deposition-precipitation, and impregnation). Fe/HAP samples (ca. 2–7 wt.% Fe) have been tested in the reaction of NOx reduction by ammonia (NH3-SCR) in the 120–500 °C interval with different NH3/NO ratios (0.6–2) at fixed contact time (0.12 s). All Fe/HAP samples were active and selective in the NH3-SCR reaction starting from ca. 350 °C. Better performances have been observed on catalysts prepared by deposition-precipitation and impregnation (about 70 % of NOx conversion and selectivity to N2 higher than 95 % at 350 °C), where α-Fe2O3 and 3D-Fe2O3 nanoclusters were present, as indicated by Mössbauer and UV-Vis-DR spectroscopies. On the opposite, paramagnetic Fe3+ centres were the predominant species on samples prepared by flash ionic exchange. Further characterization techniques (XRPD, N2-physisorption, acidity by NH3 adsorption, and H2-TPR) have concurred to elucidate Fe-sitting HAP and structure-activity relationships.
Functionalized Iron Hydroxyapatite as Eco-friendly Catalyst for NH3-SCR Reaction : Activity and Role of Iron Speciation on the Surface / S. Campisi, M.G. Galloni, S.G. Marchetti, A. Auroux, G. Postole, A. Gervasini. - In: CHEMCATCHEM. - ISSN 1867-3880. - 12:6(2020 Mar), pp. 1676-1690.
|Titolo:||Functionalized Iron Hydroxyapatite as Eco-friendly Catalyst for NH3-SCR Reaction : Activity and Role of Iron Speciation on the Surface|
|Parole Chiave:||Catalyst preparation; Denitrification; Environmental chemistry; Iron hydroxyapatite; Mossbauer spectroscopy|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
Settore CHIM/04 - Chimica Industriale
|Data di pubblicazione:||mar-2020|
|Data ahead of print / Data di stampa:||17-dic-2019|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1002/cctc.201901813|
|Appare nelle tipologie:||01 - Articolo su periodico|