In this study, a commercial silicoaluminophosphate of chabazite (CHA) structure with low addition of copper phase (ca. 2–3 wt.%) deposited from Cu-acetate, Cu-nitrate, and Cu-chloride precursors (Cu/CHA) with ionicexchange and impregnation procedures was taken into consideration thanks to its known good de-NOx activity. The Cu/CHA samples were tested in the NH3-SCR (catalytic reduction of NOx by NH3) and NH3-SCO (catalytic oxidation of NH3) reactions, in the 200–500 °C interval. Important differences of Cu aggregation on CHA surface were evidenced between the samples prepared by ionic-exchange and impregnation, as observed from Uv-DRS, EPR, and H2-TPR analyses. Well-dispersed Cu-phase on the CHA surface and more aggregated CuOx clusters were formed by depositing the Cu-phase with ionic-exchange and impregnation method, respectively. All the Cu/CHA samples were active and selective in the NH3-SCR reaction in the explored temperature interval, with enhanced performances of the sample prepared by impregnation. NH3-SCO selectivity to N2 was higher (80–95%) on the samples with lower Cu aggregation while sample with surface CuOx species was less selective (65%) but more active at lower temperatures. Temperature to obtain 50% of ammonia conversion (T50 °C) was around 250 °C, for the sample prepared by impregnation, and in the range 355–390 °C for the samples prepared by ionic-exchange. The study permitted to disclose the possibility to use Cu/CHA samples in a cascade NH3-SCR and NH3-SCO reactions in a future process for zero emissions of both NOx and NH3.
Effect of Cu deposition method on silico aluminophosphate catalysts in NH3-SCR and NH3-SCO reactions / M.L. Schiavoni, S. Campisi, A. Gervasini. - In: APPLIED CATALYSIS A: GENERAL. - ISSN 0926-860X. - 543(2017 Aug), pp. 162-172.
|Titolo:||Effect of Cu deposition method on silico aluminophosphate catalysts in NH3-SCR and NH3-SCO reactions|
SCHIAVONI, MARCO LEONARDO (Primo)
CAMPISI, SEBASTIANO (Secondo)
GERVASINI, ANTONELLA (Ultimo)
|Parole Chiave:||silicoaluminophosphate (SAPO); copper-chabazite catalysts; catalyst characterization; NH3-SCR (catalytic nitrogen oxide reduction); NH3-SCO (catalytic ammonia oxidation).|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Data di pubblicazione:||ago-2017|
|Data ahead of print / Data di stampa:||lug-2017|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.apcata.2017.06.034|
|Appare nelle tipologie:||01 - Articolo su periodico|