Characterization of the active species in the silver/alumina system for lean NOx reduction with methanol
Artikel i vetenskaplig tidskrift, 2016
Low-temperature activity and selectivity for lean NOx reduction over silver/alumina is strongly dependent on the composition of surface silver species. This motivates the present investigation of the role of the supported silver species for the lean NOx reduction with methanol. The catalyst samples, with different composition of silver species, are characterized by temperature programmed desorption of ammonia (NH3-TPD), temperature programmed reduction with hydrogen (H-2-TPR) and temperature programmed desorption with NO (NO-TPD) in oxygen excess. The small differences in acidity do not significantly influence the lean NOx reduction with methanol. However, comparison of results from H-2-TPR experiments with previous characterization by UV-vis spectroscopy shows that fairly small silver species are reduced by hydrogen, possibly small silver clusters. These small silver species are likely, in addition to others, involved in the lean NOx reduction reactions. NO-TPD experiments, in the presence of oxygen and hydrogen, reveal a shift in temperature for one of the desorption peaks from the different samples. This peak is likely related to the shift in temperature for NOx reduction during methanol-SCR conditions for the compared samples. (C) 2016 Elsevier B.V. All rights reserved.
ag-al2o3
Silver/alumina
Methanol
Engineering
p199
ethanol
Hydrogen
nitric-oxide
short-time
hc-scr
catalysts
supported silver catalysts
Lean NOx reduction
Desorption of NOx
selective catalytic-reduction
hydrogen
1993
yadera t
v2
applied catalysis b-environmental
ag/al2o3
Silver species
investigate
Chemistry
Författare
Marika Männikkö
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
Xueting Wang
Kompetenscentrum katalys (KCK)
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Magnus Skoglundh
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Kompetenscentrum katalys (KCK)
Hanna Härelind
Kompetenscentrum katalys (KCK)
Chalmers, Kemi och kemiteknik, Tillämpad kemi
Catalysis Today
0920-5861 (ISSN)
Vol. 267 76-81Styrkeområden
Transport
Materialvetenskap
Ämneskategorier (SSIF 2011)
Kemiteknik
Materialkemi
DOI
10.1016/j.cattod.2016.01.014