Acetaldehyde partial oxidation on the Au (111) model catalyst surface: C-C bond activation and formation of methyl acetate as an oxidative coupling product

Date
2015
Authors
Karatok, M.
Vovk, E. I.
Shah, A. A.
Turksoy, A.
Ozensoy, E.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract

Partial oxidation of acetaldehyde (CH3CHO) on the oxygen pre-covered Au(111) single crystal model catalyst was investigated via Temperature Programmed Desorption (TPD) and Temperature Programmed Reaction Spectroscopy (TPRS) techniques, where ozone (O3) was utilized as the oxygen delivery agent providing atomic oxygen to the reacting surface. We show that for low exposures of O3 and small surface oxygen coverages, two partial oxidation products namely, methyl acetate (CH3COOCH3) and acetic acid (CH3COOH) can be generated without the formation of significant quantities of carbon dioxide. The formation of methyl acetate as the oxidative coupling reaction product implies that oxygen pre-covered Au(111) single crystal model catalyst surface can activate C-C bonds. In addition to the generation of these products; indications of the polymerization of acetaldehyde on the gold surface were also observed as an additional reaction route competing with the partial and total oxidation pathways. The interplay between the partial oxidation, total oxidation and polymerization pathways reveals the complex catalytic chemistry associated with the interaction between the acetaldehyde and atomic oxygen on catalytic gold surfaces.

Description
Keywords
Acetaldehyde, Au(111), Methyl acetate, Oxidative coupling, Partial oxidation
Citation