Hydrogenation of aromatic hydrocarbons over supported Pt catalysts

Journal Article · Fri Oct 01 00:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1297· OSTI ID:5183476

Lin, S D; Vannice, M A ^[1]

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

Vapor-phase benzene hydrogenation was studied over Pt dispersed on SiO[sub 2], [eta]-Al[sub 2]O[sub 3], SiO[sub 2][center dot]Al[sub 2]O[sub 3], and TiO[sub 2], as well as Pt powder. Activation energies and reaction orders were independant of the support as all E[sub act] values fell between 10 and 13 kcal/mol and partial pressure dependencies were 0.6 [+-] 0.1 on H[sub 2] and 0.1 [+-] 0.1 on benzene between 317 and 356 K. However, higher specific activities were obtained with acidic supports; for example, at 333 K under 50 torr benzene and 685 torr H[sub 2], turnover frequencies increased from 0.015 s[sup [minus]1] on 0.78% Pt/[eta]-Al[sub 2]O[sub 3] and 0.033 s[sup [minus]1] on 0.96% Pt/SiO[sub 2] to 0.072 on 0.24% Pt/SiO[sub 2] [center dot] Al[sub 2]O[sub 3] and 0.078 on 0.95% Pt/TiO[sub 2]. An even larger increase occurred under 35 Torr benzene. This rate enhancement, which is similar to that found with Pd on these same supports, is associated with an additional contribution from benzene adsorbing on acidic sites on the support and reacting with spilled-over hydrogen. Significant inhibition and deactivation occurred under certain reaction conditions which altered steady-state activities. This is attributed to the concurrent formation of hydrogen-deficient surface species during benzene hydrogenation. 115 refs., 7 figs., 4 tabs.

• DOE Contract Number: FG02-84ER13276
• OSTI ID: 5183476
• Journal Information: Journal of Catalysis; (United States), Vol. 143:2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
02 PETROLEUM
BENZENE
HYDROGENATION
PLATINUM
CATALYTIC EFFECTS
ACTIVATION ENERGY
CATALYST SUPPORTS
CHEMICAL REACTION KINETICS
LOW PRESSURE
PRESSURE DEPENDENCE
SOLID SOLUTIONS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
AROMATICS
CHEMICAL REACTIONS
DISPERSIONS
ELEMENTS
ENERGY
HYDROCARBONS
KINETICS
METALS
MIXTURES
ORGANIC COMPOUNDS
PLATINUM METALS
REACTION KINETICS
SOLUTIONS
TEMPERATURE RANGE
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
020400 - Petroleum- Processing