Influence of ceria on the NOx reduction performance of NOx storage reduction catalysts
Please cite this item using this persistent URLhttp://hdl.handle.net/11693/20789
Applied Catalysis B: Environmental
- Research Paper 
Influence of ceria on the NOx storage and reduction behavior of NSR catalysts was investigated in a systematic manner over γ-Al2O3, Ba/Al, Ce/Al, Ba/Ce/Al, Pt/Al, Pt/Ce/Al and Ba/Pt/Ce/Al systems using BET, XRD, Raman spectroscopy and in situ FTIR. Although ceria promotion does not seem to have a substantial influence on the overall NOx storage capacity, it does have a clearly positive effect on the NOx reduction via H2(g) during catalytic regeneration under rich conditions which is associated with the enhancement in the total amount of activated hydrogen on the catalyst surface and lowering of the thermal threshold for hydrogen activation. A strong metal support interaction (SMSI) between Pt sites and the BaOx/CeOx domains leads to a complex redox interplay including oxidation of the precious metal sites, reduction of ceria, formation of BaO2 species as well as the formation of Pt-O-Ce interfacial sites on the Ba/Pt/Ce/Al surface. Ceria domains also act as anchoring sites for Pt species, limit their surface diffusion, enhance dispersion and hinder sintering at elevated temperatures. On the Ba/Pt/Ce/Al catalyst surface, reduction of the stored nitrates under relatively mild conditions via H2(g) initially leads to the formation of surface -OH and -NHx species and gas phase N2O, as well as the destruction of surface nitrate species, leaving bulk nitrates mostly intact. Reduction proceeds with the conversion of N2O(g) into N2(g) along with the partial loss of surface -OH and -NHx groups, dehydration and the loss of bulk nitrates. © 2013 Elsevier B.V.
Showing items related by title, author, creator and subject.
Carbon supported nano-sized Pt-Pd and Pt-Co electrocatalysts for proton exchange membrane fuel cells Kadirgan F.; Kannan, A.M.; Atilan, T.; Beyhan, S.; Ozenler, S.S.; Suzer, S.; Yörür, A. (2009)Nano-sized Pt-Pd/C and Pt-Co/C electrocatalysts have been synthesized and characterized by an alcohol-reduction process using ethylene glycol as the solvent and Vulcan XC-72R as the supporting material. While the Pt-Pd/C ...
One-step codoping of reduced graphene oxide using boric and nitric acid mixture and its use in metal-free electrocatalyst Tien H.N.; Kocabas, C.; Hur, S.H. (Elsevier, 2015)In this study, the preparation of a highly efficient metal-free electrocatalyst, boron and nitrogen codoped reduced graphene oxide (BN-rGO), with an excellent durability is reported. The BN-rGO were prepared in one step ...
In situ FT-IR spectroscopic investigation of gold supported on tungstated zirconia as catalyst for CO-SCR of NO x Kantcheva, M.; Milanova, M.; Mametsheripov, S. (2012)The possibility for application of gold supported on tungstated zirconia as catalyst in the selective catalytic reduction of NO x with CO (CO-SCR) has been investigated by means of in situ FT-IR spectroscopy. Tungstated ...