fulltext.study @t Gmail

Kinetic evaluation of direct NO decomposition and NO–CO reaction over dendrimer-derived bimetallic Ir–Au/Al2O3 catalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
45040 46395 2014 11 PDF Available
Title
Kinetic evaluation of direct NO decomposition and NO–CO reaction over dendrimer-derived bimetallic Ir–Au/Al2O3 catalysts
Abstract

•Highly dispersed Ir–Au/Al2O3 was prepared using dendrimer templating method.•Bimetallic structure correlates with activity for NO–CO and direct NO reduction reactions.•The effects of Au on the catalytic performance of Ir metal was elucidated.•Both NO–CO and direct NO decomposition reactions are structure-sensitive.

The effects of Au on the catalytic performance of Ir metal towards NO reduction by CO and direct NO decomposition have been investigated over dendrimer-derived Ir–Au bimetallic catalyst. Results were also compared to a catalyst prepared by conventional incipient wetness impregnation of metal salts. Characterization of Ir–Au bimetallic samples using scanning transmission electron microscopy, H2 chemisorption and temperature programmed desorption of NO reveals that highly dispersed Ir–Au particles can be obtained by dendrimer templating method. In-situ transmission Fourier transform infrared spectroscopy following adsorption of probe molecules (i.e., CO and NO) on the dendrimer-derived Ir–Au bimetallic sample indicated the presence of electron transfer from Ir to Au sites. In contrast, a geometric effect of Au on Ir was observed over the conventional-derived sample, consistent with X-ray photoelectron spectroscopy measurements. These properties influence the catalytic performance, with higher selectivity towards N2O and a better intrinsic catalytic turnover frequency for reduction of NO by CO and NO decomposition observed for the dendrimer-derived sample. Overall, the results suggest that both NO–CO and NO decomposition reaction are structure-sensitive reactions.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Iridium; Gold; Bimetallic; Dendrimer; Direct NO decomposition; NO–CO reaction
First Page Preview
Kinetic evaluation of direct NO decomposition and NO–CO reaction over dendrimer-derived bimetallic Ir–Au/Al2O3 catalysts
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volumes 154–155, July–August 2014, Pages 62–72
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis