Catalysts characterization
N2 adsorptionedesorption isotherms at 77 K were obtained
for alumina support and catalyst sample synthesized
respectively. The isotherm obtained for Disperal alumina
support presents a hysteresis cycle typical of a mesoporous
solid, that corresponds to IV H3 type (IUPAC classification)
ascribed to mesoporous solids that presents capillary
condensation without adsorption limitation, usually presented
in laminar pores. The impregnation of the active
phase (Ni and Co) and promoter (La) produce a slight
decrease of specific surface area, pore volume and pore size
(Table 1) produced by a partial blockage of the alumina
pores by precursor salts solution addition. However, the
addition of lanthana avoids the nucleation of a-Al2O3 and
produces a thermal stabilization of the catalysts decreasing
the specific surface area loss ascribed to ɣ to a alumina
transition [37,38].
The XRD patterns of support (a) and prepared catalyst (b)
are shown in Fig. 2. The support pattern was ascribed to ɣ-
Al2O3 which diffraction peaks match perfectly with the