"Pop-On and Pop-Off" Surface Chemistry of Alanine on Ni{111} Under Elevated Hydrogen Pressures

DOI: 10.1021/acs.jpcc.8b00186

Authors: Richard E. J. Nicklin (University of Reading; Diamond Light Source) , Andrey Shavorskiy (Advanced Light Source; MAX IV Laboratory) , Funda Aksoy Akgul (Advanced Light Source; Nigde Ömer Halisdemir University) , Zhi Liu (Advanced Light Source; ShanghaiTech University) , Roger A. Bennett (University of Reading) , Marco Sacchi (University of Surrey) , Georg Held (University of Reading)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: The Journal Of Physical Chemistry C

State: Published (Approved)
Published: March 2018

Abstract: The co-adsorption of hydrogen with a simple chiral modifier, alanine, on Ni{111} was studied using Density Functional Theory in combination with ambient-pressure X-ray photoelectron spectroscopy and X-ray absorption spectroscopy at temperatures of 300~K and above, which are representative of chiral hydrogenation reactions. Depending on the hydrogen pressure, the surface enables protons to "pop on and off" the modifier molecules, thus significantly altering the adsorption geometry and chemical nature of alanine from anionic tridentate in ultra-high vacuum to predominantly zwitterionic bidentate at hydrogen pressures above 0.1 Torr. This hydrogen-stabilised modifier geometry allows alternative mechanisms for proton transfer and the creation of enatioselective reaction environments.

Subject Areas: Chemistry

Facility: ALS