Acetic acid conversion to ketene on Cu2O(1 0 0): Reaction mechanism deduced from experimental observations and theoretical computations
Artikel i vetenskaplig tidskrift, 2021

Ketene, a versatile reagent in production of fine and specialty chemicals, is produced from acetic acid. We investigate the synthesis of ketene from acetic acid over the (3,0;1,1) surface of Cu2O(1 0 0) through analysis of the adsorption and desorption characteristics of formic and acetic acids. The results allow us to establish a reaction mechanism for ketene formation. Observations from x-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy, and temperature programmed desorption (TPD), supported by a comparison with formic acid results, suggest that acetic acid reacts with Cu2O through deprotonation to form acetate species coordinated to copper sites and hydroxylation of nearby surface oxygen sites. For formic acid the decomposition of adsorbed formate species results in desorption of CO2 and CO while, for acetic acid, high yields of ketene are observed at temperature >500 K. Modeling by density functional theory (DFT) confirms the strong interaction of acetic acid with the (3,0;1,1) surface and the spontaneous dissociation into adsorbed acetate and hydrogen atom species, the latter forming an OH-group. In an identified reaction intermediate ketene binds via all C and O atoms to Cu surface sites, in agreement with interpretations from XPS. In the vicinity of the adsorbate the surface experiences a local reorganization into a c(2 × 2) reconstruction. The total computed energy barrier for ketene formation is 1.81 eV in good agreement with the 1.74 eV obtained from TPD analysis. Our experimental observations and mechanistic DFT studies suggests that Cu2O can operate as an efficient catalyst for the green generation of ketene from acetic acid.

Heterogeneous catalysis

Scanning tunneling microscopy

Density functional theory

Ketene

X-ray photoelectron spectroscopy

Acetic acid

Författare

H. Tissot

Kungliga Tekniska Högskolan (KTH)

J. Halldin Stenlid

Alba Nova Universitetscentrum

C. Wang

Kungliga Tekniska Högskolan (KTH)

M. Panahi

Koç Üniversitesi

S. Kaya

Koç Üniversitesi

T. Brinck

Kungliga Tekniska Högskolan (KTH)

Yasmine Sassa

Chalmers, Fysik, Materialfysik

Fredrik O.L. Johansson

Uppsala universitet

Jonas Weissenrieder

Kungliga Tekniska Högskolan (KTH)

Journal of Catalysis

0021-9517 (ISSN) 1090-2694 (eISSN)

Vol. 402 154-165

Framtidens Lågdimensionella Skyrmion Material

Vetenskapsrådet (VR) (2017-05078), 2019-06-01 -- 2021-12-31.

Ämneskategorier

Oorganisk kemi

Annan kemi

Organisk kemi

Styrkeområden

Materialvetenskap

DOI

10.1016/j.jcat.2021.08.022

Mer information

Senast uppdaterat

2021-09-13