fulltext.study @t Gmail

The influence of cooling atmosphere after reduction on the catalytic properties of Au/Al2O3 and Au/MgO catalysts in CO oxidation

Paper ID Volume ID Publish Year Pages File Format Full-Text
44425 46025 2007 8 PDF Available
Title
The influence of cooling atmosphere after reduction on the catalytic properties of Au/Al2O3 and Au/MgO catalysts in CO oxidation
Abstract

Unexpected activity alterations were observed in CO oxidation upon changing the atmosphere of cooling from an inert gas to hydrogen after reduction in hydrogen at 350 °C. Different supports resulted in different trends, e.g. over Au/MgO higher activities were obtained after cooling in helium, while Au/Al2O3 showed the opposite effect, i.e., higher activities were measured after cooling in hydrogen. The higher the Au content of the catalyst the more pronounced the “cooling effect”. Contrary to pure Au/Al2O3 catalysts the addition of redox-type modifiers, such as iron, manganese and cobalt to the support, the cooling in hydrogen decreased the activity. In situ FTIR results indicated that cooling in hydrogen increases the negative charge on the supported gold nanoparticles on both supports.

Graphical abstractUnexpected activity alterations were observed in CO oxidation upon changing the atmosphere of cooling from an inert gas to hydrogen after reduction in hydrogen at 350 °C. Different supports resulted in different trends, e.g. over Au/MgO higher activities were obtained after cooling in helium, while Au/Al2O3 showed the opposite effect, i.e., higher activities were measured after cooling in hydrogen. Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Au/MgO; Au/Al2O3; Modified supported gold catalysts; CO oxidation; FTIR; Cooling effect
First Page Preview
The influence of cooling atmosphere after reduction on the catalytic properties of Au/Al2O3 and Au/MgO catalysts in CO oxidation
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 320, 22 March 2007, Pages 114–121
Authors
, , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis