Collect. Czech. Chem. Commun. 1988, 53, 1229-1238

The comparison of two preparations of a Ni-Co-Mo/Al2O3-SiO2 hydrotreating catalysts

Jolanta Grzechowiaka, Jiří Sedláčekb and Miroslav Zdražilb

a Institute of Chemistry and Technology of Petroleum and Coal, Technical University, Gdańska 7/9, 50-344 Wrocław, Poland
b Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol, Czechoslovakia


Two preparations of Ni-Co-Mo/Al2O3-SiO2 hydrorefining catalysts differing in the method of SiO2 addition were investigated by the combination of several chemical and physical methods. As the result of the modification in preparation procedure, the following changes occurred simultaneously: the increase of relative surface concentrations of active metals detected by XPS, the increase of surface acidity measured by ammonia thermodesorption, the increase in porosity, the formation of larger pores, enlargement of the particles forming the texture of surface shown by SEM and the increase of the rate of hydrodesulphurization of tetrahydrothiophene. The response of other characteristics was small: surface polarity measured by reversible adsorption of benzene and heptane, the rate of hydrodesulphurization of thiophene and the rate of decomposition of tetrahydrothiophene in nitrogen. The difference in the performance of both catalysts is explained by the combination of several factors. The necessity of combination of several characterization techniques in the study of the relation between preparation procedure and performance of the catalyst is stressed.