Hydrogenation of aromatic hydrocarbons over supported Pt catalysts. II. Toluene hydrogenation

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

DOI:https://doi.org/10.1006/jcat.1993.1298· OSTI ID:5183357

Lin, S D; Vannice, M A ^[1]

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

Vapor-phase toluene hydrogenation was investigated over Pt supported 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 with benzene, activation energies and reaction orders had no dependence on the support. The E[sub A] values were 12 [+-] 2 kcal/mol and the partial pressure dependence on toluene was near zero, i.e., essentially the same as for benzene; however, the H[sub 2] pressure dependence increased from less than 0.7 at 333 K to over unity at 373 K. The turnover frequencies were four times higher with the most acidic support compared to the least acidic support, i.e., at 333 K under 50 Torr toluene and 685 Torr H[sub 2], the TOF on 0.24% Pt/SiO[sub 2][center dot]Al[sub 2]O[sub 3] was 0.112 s[sup [minus]1], whereas it was 0.027 s[sup [minus]1] on 0.96% Pt/SiO[sub 2]. This rate enhancement is attributed to an additional hydrogenation reaction occurring via hydrogen spilling over onto the support and reacting with aromatic molecules adsorbed on acid sites on the oxide. Deactivation was less of a problem with toluene compared to benzene. 48 refs., 5 figs., 3 tabs.

• OSTI ID: 5183357
• 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
PLATINUM
CATALYTIC EFFECTS
TOLUENE
HYDROGENATION
ACTIVATION ENERGY
CATALYST SUPPORTS
CHEMICAL REACTION KINETICS
LOW PRESSURE
PRESSURE DEPENDENCE
SOLID SOLUTIONS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
ALKYLATED AROMATICS
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