Alcohol decomposition by reverse spillover

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1325· OSTI ID:5036122

Chen, B; Falconer, J L ^[1]

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1. Univ. of Colorado, Boulder, CO (United States)

Temperature-programmed desorption (TPD) was used to study methanol, ethanol, and 1-propanol decomposition on Al[sub 2]O[sub 3] and Ni/Al[sub 2]O[sub 3] catalysts. These alcohols adsorb on the Al[sub 2]O[sub 3] support of Ni/Al[sub 2]O[sub 3] and dehydrogenate by reverse spillover to the Ni surface. Thus, the presence of Ni dramatically increases their decomposition rates. Methanol adsorbed on Al[sub 2]O[sub 3] alone decomposes to form (CH[sub 3])[sub 2]O at lower temperature and CO, H[sub 2], and CO[sub 2] above 600 K. On Ni/Al[sub 2]O[sub 3], most CH[sub 3]OH dehydrogenates to form CO and H[sub 2]. Ethanol adsorbed on Al[sub 2]O[sub 3] mostly dehydrates to form C[sub 2]H[sub 4] and (C[sub 2]H[sub 5])[sub 2]O, but C[sub 2]H[sub 4]O and H[sub 2] are also observed. On Ni/Al[sub 2]O[sub 3], C[sub 2]H[sub 5]OH dehydrogenation to CO, H[sub 2], and surface carbon is the main reaction. 1-Propanol decomposes on Al[sub 2]O[sub 3] to form C[sub 3]H[sub 6], H[sub 2], (C[sub 3]H[sub 7])[sub 2]O, and C[sub 3]H[sub 6]O. When Ni is present, propanol decomposition to H[sub 2], CO, and surface carbon is the dominant process, but some C[sub 3]H[sub 6], C[sub 3]H[sub 6]O, and CO[sub 2] also form. On Al[sub 2]O[sub 3], the alcohols decomposition rates are in the order 1-C[sub 3]H[sub 7]OH > C[sub 2]H[sub 5]OH > CH[sub 3]OH, but on Ni/Al[sub 2]O[sub 3] the rates are almost identical. The increase in the decomposition rate of alcohols, when Ni is present, is attributed to alcohol diffusion along the Al[sub 2]O[sub 3] surface and decomposition on the Ni surface or at the Ni-Al[sub 2]O[sub 3] interface. The diffusivity of CH[sub 3]O on the Al[sub 2]O[sub 3] surface at 534 K is estimated to be larger than 6.6 x 10[sup [minus]11] cm[sup 2]/s. 38 refs., 7 figs., 3 tabs.

• OSTI ID: 5036122
• Journal Information: Journal of Catalysis; (United States), Vol. 144:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
ALUMINIUM OXIDES
CATALYTIC EFFECTS
ETHANOL
DECOMPOSITION
METHANOL
NICKEL COMPLEXES
PROPANOLS
CATALYST SUPPORTS
HETEROGENEOUS CATALYSIS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
ALCOHOLS
ALUMINIUM COMPOUNDS
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
HYDROXY COMPOUNDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
TEMPERATURE RANGE
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
100300 - Synthetic Fuels- Properties & Composition- (1990-)