Surface characteristics and catalytic activity of binary oxides of alumina-yttria

• Published in: Materials research bulletin Vol. 29; no. 6; pp. 651 - 658
• Main Authors: Jayasree, J., Narayanan, C.S.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.06.1994; Amsterdam Elsevier Science
• Subjects: 400201 - Chemical & Physicochemical Properties; ALCOHOLS; ALUMINIUM COMPOUNDS; ALUMINIUM OXIDES; Catalysis; Catalysts: preparations and properties; CATALYTIC EFFECTS; CHALCOGENIDES; CHEMICAL ANALYSIS; CHEMICAL PREPARATION; Chemistry; COHERENT SCATTERING; DIFFRACTION; ELECTRON MICROSCOPY; Exact sciences and technology; General and physical chemistry; GLYCOLS; GRAVIMETRIC ANALYSIS; HYDROXY COMPOUNDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KETONES; MAGNETIC RESONANCE; MICROSCOPY; NUCLEAR MAGNETIC RESONANCE; ORGANIC COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PH VALUE; QUANTITATIVE CHEMICAL ANALYSIS; RESONANCE; SCANNING ELECTRON MICROSCOPY; SCATTERING; SURFACE PROPERTIES; SYNTHESIS; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; THERMAL ANALYSIS; THERMAL GRAVIMETRIC ANALYSIS; TRANSITION ELEMENT COMPOUNDS; X-RAY DIFFRACTION; YTTRIUM COMPOUNDS; YTTRIUM OXIDES; Hammett indicators; alumina; yttria; limonene oxide; Scanning electron microscopy; Aluminium Oxides; Yttrium Oxides; Transition metal Compounds; Thermogravimetry; Acidity; Catalyst activity; Alumina; Coprecipitation; Physicochemical properties; Thermal stability
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/0025-5408(94)90121-X

A series of different compositions of Al 2O 3Y 2O 3 catalysts were prepared by coprecipitation with aqueous ammonia. The structure, thermal stability and surface properties of the catalysts were determined using XRD, TGA, SEM and MAS 27AlNMR. Acidity and basicity of catalysts were determined using Hammett indicators and surface area by BET method. Surface area and Bronsted acidity of the catalysts decreased with increasing amount of Y 2O 3. No basic sites were observed over catalyst samples with higher Y 2O 3 content. (+)-Limonene oxide isomerization was carried out at 110°C over the catalysts. The activity and selectivity of catalysts varied with composition. Catalysts with high alumina content yielded more diol while less alumina containing samples produced more ketones.