Date of Award
Open Access Dissertation
Christopher T Williams
Hydrogenation of C=C in α-methylcinnamic acid (MCA) is studied by both kinetic and spectroscopic method. Kinetic study was in a semi-batch reactor. The reaction activity is strongly solvent dependent, while selectivity remains almost unaffected. The reaction is zero order in hydrogen pressure and first order in MCA. The presence of cinchonidine does not affect the reaction order with respect to either acid or H2 pressure, but has a significant inhibiting effect on the reaction rate. The catalyst exhibits stable activity during the reaction with no sign of deactivation. The adsorption and hydrogenation in dichloromethane, isopropanol and 1, 4-Dioxane over the concentration range 2-16 mM have been studied on Al2O3 and Pd/Al2O3 using in-situ attenuated total reflection infrared (ATR-IR) spectroscopy. For MCA in dichloromethane, C=O stretching vibrations arising from adsorbed monomer (1710 cm-1) and dimer (1684 cm-1) species were observed. In the case of dissociatively adsorbed carboxylate, the typical asymmetric (1522 cm-1) and symmetric (1378 cm-1) vibrations are observed. For MCA in isopropanol and 1, 4-Dioxane, on both Al2O3 and 5wt% Pd/Al2O3, the predominant form of adsorbed MCA is as a bridging carboxylate species.
Sun, X.(2013). Enantioselective Hydrogenation of α-Methylcinnamic Acid Over PD/AL2O3: A Spectroscopic and Kinetic Study. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/596