Journal
ACS CATALYSIS
Volume 5, Issue 1, Pages 301-309Publisher
AMER CHEMICAL SOC
DOI: 10.1021/cs500880w
Keywords
perovskite; PrMnO3+delta; silver; catalysis; CO oxidation
Categories
Funding
- Council of Scientific and Industrial Research (CSIR)
- DST-JSPS [GAP1962]
Ask authors/readers for more resources
Unambiguous evidence has been obtained to explain the presence and effects of both framework and extra-framework silver on catalytic properties of Pr(Ag)MnO3+delta perovskite type materials, using various tools such as XPS, HR-TEM, O-2-TPD, and H-2-TPR analysis. Three types of Ag-incorporated PrMnO3 perovskite samples were synthesized by means of Ag partial substitution in perovskite lattice and Ag dispersion on the surface of the synthesized perovskite phase, using two different calcination temperatures of 200 and 550 degrees C. The amount of silver used was 1 wt % (0.000225 mol), in all three catalysts. On the basis of extensive characterization studies, it was clearly explained that the partially substituted Ag for Pr is present in the lattice along with Pr at the A site of the ABO(3) perovskite structure. The Ag surface incorporated PrMnO3+delta sample calcined at 550 degrees C shows both surface metallic silver and partially substituted Ag in perovskite lattice, whereas Ag2O nanoparticles were observed on the surface in the case of another sample calcined at 200 degrees C. All of the synthesized materials were evaluated for their CO and soot oxidation activity, considering the renewed interest in Ag promoted catalytic materials and ambiguity about its location in the perovskite structure as well as its role in promoting catalytic and other properties of perovskite type materials. Perovskites with surface Ag species show better catalytic activity than the Ag substituted counterpart. This improved and better activity of Ag dispersed samples was because of the presence of the surface active redox couple of Ag/Ag2O, which facilitates the surface redox reaction pathway of CO and soot oxidation reactions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available