Influence of oxonium ion and carbenium ion stabilities on the alcohol/H-ZSM-5 interaction

Journal Article · Tue Apr 01 00:00:00 EST 1986 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(86)90331-3· OSTI ID:5205997

Aronson, M T; Gorte, R J; Farneth, W E

The authors have examined the adsorption of methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, and 2-methyl-2-propanol on H-ZSM-5 using temperature-programmed desorption (TPD) and thermogravimetric analysis (TGA). For each of the alcohols except 1-butanol, there exists a clearly defined desorption state corresponding to one alcohol molecule per Al atom in the zeolite. For 2-methyl-2-propanol and 2-propanol, this molecule at the Al site completely reacts to olefin products and water; however, reaction occurs at 295 K for 2-methyl-2-propanol, while 2-propanol does not react until 360 K. Most of the methanol, ethanol, and 1-propanol adsorbed at the Al sites at this coverage desorbs unreacted. A substantial amount of the 1-butanol adsorbed near the Al sites reacts, but differs from the other alcohols in that it reacts through a dibutyl ether intermediate. These results can be understood in terms of the stabilities of the carbenium ion intermediates which can be formed during reaction. A potential energy scheme, based on gas-phase proton affinity, is developed. This scheme provides a formalism for explaining relative reactivities of alcohols on H-ZSM-5 in TPD. 25 references.

• Research Organization: Univ. of Pennsylvania, Philadelphia (USA)
• OSTI ID: 5205997
• Journal Information: J. Catal.; (United States), Vol. 98:2
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
BUTANOLS
ADSORPTION
ETHANOL
METHANOL
PROPANOLS
ZEOLITES
SORPTIVE PROPERTIES
ALKENES
ALUMINIUM
CATALYTIC EFFECTS
CATALYTIC REFORMING
DESORPTION
OXONIUM IONS
REACTION INTERMEDIATES
SYNTHESIS
WATER
ALCOHOLS
CHARGED PARTICLES
CHEMICAL REACTIONS
ELEMENTS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
MATERIALS
METALS
MINERALS
MOLECULAR IONS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
REFORMER PROCESSES
SORPTION
SURFACE PROPERTIES
010408* - Coal
Lignite
& Peat- C1 Processes- (1987-)