Low temperature and low pressure CO oxidation on gold clusters supported on MgO(100)

Autor:	Claude Henry, G. Sitja, O. Meerson
Rok vydání:	2005
Předmět:	Reaction mechanism Materials science Adsorption Colloidal gold Nanoparticle Physical chemistry Infrared spectroscopy High-resolution transmission electron microscopy Evaporation (deposition) Atomic and Molecular Physics and Optics Catalysis
Zdroj:	The European Physical Journal D. 34:119-124
ISSN:	1434-6079 1434-6060
DOI:	10.1140/epjd/e2005-00131-8
Popis:	CO oxidation has been investigated on Au/MgO(100) model catalysts at RT and low pressure. The gold particles prepared by UHV evaporation on clean MgO surfaces are characterized by HRTEM. The gold particles are FCC single crystals or multiple twins with five-fold symmetry. Infrared spectroscopy indicates that two types of adsorption sites are present which correspond to loosely and strongly bound CO. The equilibrium CO coverage for the strongly bound CO is smaller than 0.1 ML. CO titration experiments show that oxygen does not dissociate on the gold nanoparticles. The CO oxidation reaction is studied at RT by molecular beam methods. A steady state CO reaction probability up to 0.50 is measured, for the first time at low pressure, for gold particles with a mean size of 1.5 nm. A reaction mechanism is proposed in which CO adsorbed on low coordinated gold atoms reacts with oxygen adsorbed molecularly, possibly at the Au/MgO interface.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a8413cce62487505728aa9d8c38b3843 https://doi.org/10.1140/epjd/e2005-00131-8 Zobrazit plný text záznamu Plný text ve formátu PDF