Year: 2018
Type: article
Abstract: Copper-exchanged zeolites catalyze the selective catalytic reduction (SCR) of NO x by NH 3 in diesel vehicles.Previously proposed reaction mechanisms were based on spectroscopic observations of the catalyst's structure under steady-state conditions.The group at PSI exploited time-resolved quick-EXAFS and transient experimentation to demonstrate the role of different Cu species in Cu-SSZ-13 under SCR conditions.Cu(i) oxidation was found to be inhibited by NH 3 coordination and represents the rate-limiting step below 250 °C.During the relaxation of inhibition, a fourfold coordinated Cu(ii) species was identified as the key reaction intermediate.These results could be transferred to catalytic experiments on the honeycomb catalyst highlighting the power of the reported spectroscopic approach.
Authors: Aaron Johnson, Ashkan Karimi, Verena Schreier, Nathan W. Luedtke
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4213139395