Effect of capping agent on cyclohexanone hydrogenation using colloidal Pt nanocatalysts

CHED 977

Kimberly A. Manbeck, Carrie A. Kauffman, cam003@lvc.edu, Jason K. Navin, and Anderson L. Marsh, marsh@lvc.edu. Department of Chemistry, Lebanon Valley College, 101 N. College Ave., Annville, PA 17003
The hydrogenation of carbonyl bonds lies at the heart of various chemical industries, ranging from pharmaceuticals to fragrances. Our efforts in this area take advantage of colloidal platinum nanoparticles synthesized in the 1-10 nm size range. In order to prevent aggregation in solution, these colloidal nanocatalysts are capped with the stabilizing agent poly(vinylpyrrolidone), or PVP, of various molecular weights. It is important to understand how this polymer capping agent may influence catalytic activity and selectivity. To solve this problem, we are combining nanocatalyst characterization by TEM (for determining particle size) and MALDI-MS (for determining amount of capping agent per nanoparticle) with reaction studies. Through measurement of turnover rates for cyclohexanone hydrogenation by nanocatalysts stabilized with different molecular weights of PVP, we are connecting reaction activity and selectivity with catalyst properties. By combining this knowledge together, we will elucidate molecular scale properties that influence activity and selectivity for colloidal nanocatalysts.