Hydrogenation of phenylethanol and acetylcyclohexane over Pt

Journal Article · Sun May 01 00:00:00 EDT 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1155· OSTI ID:7197515

Sanders, D K; Lin, S D; Vannice, M A ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

The control of intramolecular selectivity when both unsaturated C[double bond]C bonds and carbonyl groups are present is of commercial importance. Group VIII metals, particularly Ni and Pt, are used to hydrogenate aromatic hydrocarbons, and copper chromite catalysts have routinely been used to hydrogenate carbonyl groups in aromatic molecules as they are relatively inactive for hydrogenating aromatic rings. The authors have recently studied acetophenone (C[sub 6]H[sub 5]COCH[sub 3]) hydrogenation over Pt to determine the relativistic rates of phenylethanol (C[sub 6]H[sub 5]CHOHCH[sub 3]) formation versus acetylcyclohexane (C[sub 6]H[sub 11]COCH[sub 3]) formation and to examine the influence of the support on product selectivity. Phenylethanol constituted about 60-70 mole% of the product over typical Pt catalysts such as Pt/SiO[sub 2] and Pt/[eta]-Al[sub 2]O[sub 3], even at conversions up to 50%; however, the use of TiO[sub 2] as a support shifted the selectivity to 90% or higher. There are numerous products possible in this reaction network, and two major considerations exist to account for the high selectivity to PhEt, especially at high acetophenone conversions-the intrinsic hydrogenation rates of the various compounds or their relative surface coverages under reaction conditions, i.e., competitive adsorption. To see which of these two factors is predominant in this reaction system, the vapor-phase hydrogenation of phenylethanol (PhEt) and acetylcyclohexane (AcCy) was studied over Pt and compared to acetophenone (AcPh) hydrogenation rates. Neither PhEt nor AcCy hydrogenation over Pt has been studied; consequently, the first specific activities of these reactions are reported here. 6 refs., 3 figs., 3 tabs.

• OSTI ID: 7197515
• Journal Information: Journal of Catalysis; (United States), Vol. 147:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

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PHYSICAL AND ANALYTICAL CHEMISTRY
ALCOHOLS
HYDROGENATION
KETONES
PLATINUM
CATALYTIC EFFECTS
ALKYLATED AROMATICS
CHEMICAL REACTION KINETICS
AROMATICS
CHEMICAL REACTIONS
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HYDROXY COMPOUNDS
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400201* - Chemical & Physicochemical Properties