A combined experimental and theoretical study of methyl acetoacetate adsorption on Ni{100}

Tsaousis, P., Ontaneda, J., Bignardi, L., Bennett, R. A. ORCID: https://orcid.org/0000-0001-6266-3510, Grau-Crespo, R. ORCID: https://orcid.org/0000-0001-8845-1719 and Held, G. (2018) A combined experimental and theoretical study of methyl acetoacetate adsorption on Ni{100}. The Journal of Physical Chemistry C, 122 (11). pp. 6186-6194. ISSN 1932-7447 doi: 10.1021/acs.jpcc.8b00204

Abstract/Summary

The enantio-selective hydrogenation of methyl acetoacetate (MAA) over modified Ni-based catalysts is a key reaction in the understanding of enantioselective heterogeneous catalysis as it represents the only example of this class of reactions catalysed by base metals. Yet, there is very little molecular-level information available about the adsorption complex formed by the reactants on Ni surfaces. Here, we report a combined experimental and theoretical study of the adsorption of MAA on the Ni{100} surface. X-ray photoelectron spectroscopy shows that MAA forms stable multilayers at low temperatures, which desorb between 200 K and 220 K. At higher temperatures a single chemisorbed layer is formed, which decomposes between 300 K and 350 K. Density functional theory modelling predicts an enolate species with bidentate coordination as the most stable chemisorbed species. Comparison of photoelectron spectroscopy and X-ray absorption data with simulations using this adsorption model show good qualitative and quantitative agreement. The molecular plane is tilted with respect to the surface plane by about 50deg. This breaking of symmetry provides a mechanism for the enantio-selective hydrogenation.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/75985
Identification Number/DOI	10.1021/acs.jpcc.8b00204
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Publisher	American Chemical Society
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