ENANTIOSELECTIVE HYDROGENATION OF 1-PHENYL-1,2-PROPANODIONE ON Pt/ ZrO2 CATALYSTS

摘要: The enantioselective hydrogenation of 1-phenyl-1,2-propanedione at 298K and pressure 40 bar H 2 over zirconia supported Pt catalysts has been studied. Three different were prepared : i) ZrO - P obtained by a precipitation procedure from ZrOCl ii) MSZrO sol-gel using cetryltrimethylammonium bromide (CTMABR) as surfactant to get mesostructured solid iii) CNTsZrO after impregnation carbon nanotubes with ZrO(NO) 3 followed pyrolisis calcination. (1wt%) was introduced on the support an aqueous solution PtCl 6 . characterized nitrogen adsorption-desorption isotherms 77 K, hydrogen chemisorption, XRD TEM techniques. reactions carried out in stainless steel batch reactor cyclohexane solvent cinchonidine chiral modifier. presence CD reaction medium is necessary induce enantiomeric excess (ee) desired product R-1phenyl-1 hydroxi-2-propanone. In all studied systems, relation between enantioselectivity concentration added situ exhibits bell type curve; indicative importance competitive adsorption modifier substrate catalyst surface. On other hand, confinement effect led important enhancement activity those supports, mainly Pt/CNTsZrO catalyst.