Surface Science studies of Tartaric Acid on Ni(110)

Enantioselective surface reactions represent the ultimate expression of selectivity in catalysis, involving stereodirecting processes where only one optical component of a product is formed. At present, however, the technique of catalyst modification is imperfect and the knowledge of the surface structure of the solid insufficient. The purpose of this thesis is to provide an understanding of the various phenomena occurring on solid enantioselective catalyst surfaces. For this purpose, model stereodirecting surfaces have been created by the adsorption of the chiral modifier, (R,R)-tartaric acid, and (S,S)-TA, on a well-defined Ni(110) single crystal surface. This chiral molecule is well known for stereodirecting the enantioselective hydrogenation of beta-keto-esters. RAIRS, TPD, LEED and STM data presented in this thesis show that when tartaric acid molecules adsorb on a Ni(110) surface, a complex adsorption phase diagram is obtained, where the chemical identity and two-dimensional order of the adsorbed species varies significantly as a function of coverage and temperature. The Chirality is expressed by creating a chiral footprint at the surface linked to the adsorbed molecule.