Effect of Cu deposition method on silico aluminophosphate catalysts in NH3-SCR and NH3-SCO reactions
Articolo
Data di Pubblicazione:
2017
Citazione:
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.
Abstract:
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.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
silicoaluminophosphate (SAPO); copper-chabazite catalysts; catalyst characterization; NH3-SCR (catalytic nitrogen oxide reduction);
NH3-SCO (catalytic ammonia oxidation).
Elenco autori:
M.L. Schiavoni, S. Campisi, A. Gervasini
Link alla scheda completa: