Acid SAPO-34-based microporous catalysts with chabasite structure have been tested for the oxidative dehydrogenation of ethane in the temperature range 550-700degreesC. Pure acid and La/Na-containing samples were monitored and very interesting catalytic performances were achieved at 550-700degreesC (75-60% C2H4 selectivity and 5-30% ethane conversion) with respect to those reported for both acid zeolites and metal oxides. These performances correlated to the Bronsted acidity probed by FTIR spectroscopy and temperature-programmed desorption of NH3. The number of Bronsted acid sites located at the bridging hydroxyls (3626-3600 cm(-1)) in acidic SAPO-34 was higher than in La- and Na-containing samples, which showed also a larger amount of P-OH at framework defects. Lewis acidity induced by the presence of La and Na ions also influenced the reactivity of the SAPO-34-based catalysts.
Titolo: | Acid SAPO-34 Catalysts for Oxidative Dehydrogenation of ehane |
Autori Riconosciuti: | |
Autori: | L. MARCHESE; A. FRACHE; G. GATTI; S. COLUCCIA; L. LISI; G. RUOPPOLO; G. RUSSO; H.O. PASTORE |
Data di pubblicazione: | 2002 |
Abstract: | Acid SAPO-34-based microporous catalysts with chabasite structure have been tested for the oxidative dehydrogenation of ethane in the temperature range 550-700degreesC. Pure acid and La/Na-containing samples were monitored and very interesting catalytic performances were achieved at 550-700degreesC (75-60% C2H4 selectivity and 5-30% ethane conversion) with respect to those reported for both acid zeolites and metal oxides. These performances correlated to the Bronsted acidity probed by FTIR spectroscopy and temperature-programmed desorption of NH3. The number of Bronsted acid sites located at the bridging hydroxyls (3626-3600 cm(-1)) in acidic SAPO-34 was higher than in La- and Na-containing samples, which showed also a larger amount of P-OH at framework defects. Lewis acidity induced by the presence of La and Na ions also influenced the reactivity of the SAPO-34-based catalysts. |
Editore: | Academic Press Incorporated:6277 Sea Harbor Drive:Orlando, FL 32887:(800)543-9534, (407)345-4100, EMAIL: ap@acad.com, INTERNET: http://www.idealibrary.com, Fax: (407)352-3445 |
Volume: | 208 |
Pagina iniziale: | 479 |
Pagina finale: | 484 |
Parole Chiave: | SAPO-34; LaAPSO-34; oxidative dehydrogenation; ethane; Lewis and Bronsted acidity |
Rivista: | JOURNAL OF CATALYSIS |
Appare nelle tipologie: | 03A-Articolo su Rivista |