CHARACTERIZATION OF ALUMINA-BASED HYDROTREATED CATALYSTS PREPARED BY SOL-GEL METHODS

Alumina-based catalysts with various molybdenum loadings were prepared by two different methods. (1) The sol resulting from hydrolysis of aluminium tri(sec-butylate) (ATB) was mixed with a solution of ammonium heptamolybdate in butanediol (AHM)B. (2) The gel was obtained by hydrolysis of a mixture of two solutions: (i) ATB in 2-butanol and (ii) (AHM)B. The resulting gels with various Mo loadings were dried and calcined at 573 and 773 K to give the common oxide precursors, which were subsequently sulfided to give the final active phases. Physico-chemical techniques (chemical analysis, pore volume measurements, XRD, Raman spectroscopy) were used in order to evaluate the successive steps of the preparation. The molybdenum dispersion and the sulfiding rate were determined by XPS analysis.