Electrochemical evaluation of the morphology and enantioselectivity of Pt/graphite

Cinchona-modified Pt/graphite is enantioselective for the hydrogenation of ethyl pyruvate to ethyl lactate at I bar pressure and 293 K. Cyclic voltammetry has been used to investigate (i) the surface morphology of the Pt particles in terms of the terraces, steps and kinks present in as-received and conditioned catalysts, (ii) the adsorption of the alkaloids cinchonidine, cinchonine and dihydrocinchonidine at conditioned surfaces and (iii) the changes in morphology that occur as catalysts are sintered. A reduction in the enantiomeric excess observed over sintered catalysts is interpreted in terms of the morphological changes observed. (C) 2001 Elsevier Science B.V. All rights reserved.