Characterization and performance for propane oxidative dehydrogenation of Li-modified MoO3/Al2O3 catalysts

MARÍA C. ABELLO, MANUEL F. GÓMEZ, MÓNICA L. CASELLA, OSMAR A. FERRETTI, MIGUEL A. BAÑARES, JOSÉ L. GARCÍA FIERRO

APPLIED CATALYSIS A-GENERAL

Elsevier

Lugar: Amsterdam, The Netherlands; Año: 2003 vol. 251 p. 435 - 447

0926-860X

Oxidative dehydrogenation of propane has been studied on Mo/γ-Al2O3 catalysts with 13 wt.% of MoO3 and promoted with Li. The changes induced on catalysts when the support is doped with different amounts of Li (from 0.3 to 1.2 wt.%) have been studied by BET, AAS, XRD, SEM-EDAX, TPR, DRS, XPS, Raman spectroscopy and isopropanol decomposition. The characterization of the samples showed important changes in: texture, Mo supported structure, acid–base properties and reducibility. The Li replaces Brønsted acid sites and decreases the strength of the terminal Mo=O bond. The change in the strength of the terminal Mo=O bond does not correlate with the decrease in Mo species reducibility or with the decrease in propane conversion. This behavior suggests that the terminal Mo=O bond is not the active sites for ODH of propane. The selectivity to propene increases at lower conversion whereas at higher values it leveled off around 25%.