Jabłońska, M;
Beale, AM;
Nocuń, M;
Palkovits, R;
(2018)
Ag-Cu based catalysts for the selective ammonia oxidation into nitrogen and water vapour.
Applied Catalysis B: Environmental
, 232
pp. 275-287.
10.1016/j.apcatb.2018.03.029.
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Abstract
XRD, BET, H 2 -TPR, UV–vis-DRS, XPS and XAFS were used to characterize a series of Ag and/or Cu – Ag (1–5%), Cu (10–15%) or Ag-Cu (1–1, 1–10, 1.5–10, 5–5% of metal) – supported on γ-Al 2 O 3 . Correlation between physicochemical properties, catalytic activity and selectivity in NH 3 -SCO were thoroughly investigated. Silver species mainly in the form of Ag 2 O on the Ag/Al 2 O 3 catalysts led to enhanced activity together with drop in N 2 selectivity with increasing silver loading up to 5%. A mixture of CuO and CuAl 2 O 4 formed on the Cu/Al 2 O 3 catalysts. Easily reducible highly dispersed CuO x promoted the activity of the catalysts, while bulk CuO x and CuAl 2 O 4 decreased N 2 selectivity up to 500 °C. The activity of all Cu-containing materials was inferior to Ag-containing ones. Thus, the gap between the high conversion temperature over Cu/Al 2 O 3 and low N 2 selectivity over Ag/Al 2 O 3 was bridged by applying the Ag-Cu/Al 2 O 3 catalysts, with the optimum loading of 1.5 and 10 wt.% for silver and copper, respectively. NH 3 -TPD, NH 3 -TPSR and in situ FTIR were used to determine the in situ selective catalytic reduction (i-SCR) mechanism over 1.5% Ag/Al 2 O 3 , 10% Cu/Al 2 O 3 and 1.5% Ag-10% Cu/Al 2 O 3 respectively. The i-SCR mechanism involved the partial oxidation of NH 3 into NO x species, along with adsorbed NO x species interacting with adsorbed ammonia (NH x species) and being reduced to reaction products.
Type: | Article |
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Title: | Ag-Cu based catalysts for the selective ammonia oxidation into nitrogen and water vapour |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/j.apcatb.2018.03.029 |
Publisher version: | https://doi.org/10.1016/j.apcatb.2018.03.029 |
Language: | English |
Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | Alumina, Silver oxide species, Copper oxide species, Selective ammonia oxidation, Reaction mechanism |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
URI: | https://discovery.ucl.ac.uk/id/eprint/10047828 |
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