Characterization of the acidic properties of niobia-containing aerogels with [[sup 18]O]ethanol dehydration

Journal Article · Tue Mar 01 00:00:00 EST 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(94)90037-X· OSTI ID:6858929

DeCanio, E C; Nero, V P ^[1]; Ko, E I ^[2]

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1. Texaco R D Department, Beacon, NY (United States)
2. Carnegie Mellon Univ., Pittsburgh, PA (United States)

DeCanio et al. have recently reported the results of a novel mass spectral temperature-programmed reactions study (TPRS) of the dehydration of isotopically labelled ethanol ([[sup 18]O]ethanol) adsorbed on [gamma]-alumina and flouride-modified alumina. Their key finding is that there are two isotopomeric ether products, (C[sub 2]H[sub 5]O)[sub 2][sup 18]O and (C[sub 2]H[sub 5]O)[sub 2], in addition to ethene. This result suggests that adsorbed ethoxide can form via two routes: (i) by dissociative adsorption on Lewis acid site giving rise to the [sup 18]O-containing ethoxide and (ii) by the nucleophilic attack of the surface oxide on ethanol which is probably activated toward C-O bond cleavage by interacting with a Bronsted acid site. Thus, the product distribution following the adsorption of [[sup 18]O]ethanol provides useful information on the acidic properties of oxides, especially with respect to the nature of Lewis versus Bronsted acid sites. In this note, the authors present results which show that in using this technique to study a series of niobia-containing aerogels, the authors found evidence of stronger Bronsted acid sites on supported niobia than on bulk niobia. 9 refs., 3 figs., 1 tab.

• OSTI ID: 6858929
• Journal Information: Journal of Catalysis; (United States), Vol. 146:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
ETHANOL
DEHYDRATION
NIOBIUM OXIDES
CATALYTIC EFFECTS
ALUMINIUM OXIDES
BROENSTED ACIDS
CATALYST SUPPORTS
ETHYLENE
GELS
LABELLED COMPOUNDS
LEWIS ACIDS
OXYGEN 18
ALCOHOLS
ALKENES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
COLLOIDS
DISPERSIONS
EVEN-EVEN NUCLEI
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
ISOTOPES
LIGHT NUCLEI
NIOBIUM COMPOUNDS
NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
REFRACTORY METAL COMPOUNDS
STABLE ISOTOPES
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties
100200 - Synthetic Fuels- Production- (1990-)