Adsorption of aspartic acid on Ni{100}: a combined experimental and theoretical study

Quevedo, W., Ontaneda, J., Large, A., Seymour, J. M., 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. (2020) Adsorption of aspartic acid on Ni{100}: a combined experimental and theoretical study. Langmuir, 36 (32). pp. 9399-9411. ISSN 0743-7463 doi: 10.1021/acs.langmuir.0c01175

Abstract/Summary

Understanding the interaction of amino acids with metal surfaces is essential for the rational design of chiral modifiers able to confer enantioselectivity to metal catalysts. We present here an investigation of the adsorption of aspartic acid (Asp) on the Ni{100} surface, using a combination of synchrotron X-Ray Photoelectron Spectroscopy (XPS) and Near-Edge X-ray Absorption Fine Structure (NEXAFS), and Density Functional Theory (DFT) simulations. Based on the combined analysis of the experimental and simulated data, we can identify the dominant mode of adsorption as a pentadentate configuration with three O atoms at the bridge sites of the surfaces, and the remaining oxygen atom and the amino nitrogen are located on atop sites. From temperature-programmed XPS measurements it was found that Asp starts decomposing above 400 K, which is significantly higher than typical decomposition temperatures of smaller organic molecules on Ni surfaces. Our results offer valuable insights for understanding the role of Asp as a chiral modifier of nickel catalyst surfaces for enantioselective hydrogenation reactions.