Raman spectroscopic evidence for the formation of silicomolybdic entities on a Mo/HY zeolite catalyst

• Published in: Microporous and mesoporous materials Vol. 80; no. 1; pp. 275 - 278
• Main Authors: Plazenet, Guillaume, Martin, Catherine, Payen, Edmond, Rebours, Bernadette, Lynch, John
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.05.2005; Elsevier
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; HY zeolite; Hydrotreatment; Ion-exchange; Oxidic precursor; Porous materials; Raman spectroscopy; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolites: preparations and properties; HY zeolite; Hydrotreatment; Raman spectroscopy; Oxidic precursor; Heteropolysalt; Transition metal; Zeolite; Molybdenum; Precursor; Supported catalyst; Molecular sieve; Heterogeneous catalysis; Raman spectrometry; Catalyst
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2005.01.002

Mo/Ze catalysts prepared by incipient wetness impregnation of a Faujasite zeolite with ammonium heptamolybdate solutions have been characterized after calcination at 500 °C and transfer in wet atmosphere. Raman spectroscopy clearly evidences the formation of [SiMo 12O 40] 4− heteropolyanions. This formation, through extraction of Si atoms, is not observed before the calcination, the Anderson [AlMo 6O 24H 6] 3− entity being the main species formed during the impregnation–maturation.