A study on the preparation of supported metal oxide catalysts using JRC-reference catalysts. I. Preparation of a molybdena–alumina catalyst. Part 1. Surface area of alumina Original Research Article

This is the first report of a group study on the preparation of a MoO3/Al2O3 catalyst to find predominant preparation parameters for better and reproducible catalyst preparations. Variously prepared MoO3/Al2O3 catalysts possessing 13 wt% MoO3 were subjected to multiprong characterizations and catalytic tests. It was found that the surface area of the support was the most predominant preparation parameter for the dispersion of Mo oxide species; the dispersion increased as the surface area of the support increased. The formation of crystalline MoO3 was observed at a surface Mo concentration higher than 3.2 Mo nm−2. With sulfided MoO3/Al2O3, it was established that the dispersion of Mo sulfide species increased with increasing surface area of the support and was in proportion to that of Mo oxide precursor species. The hydrodesulfurization activity of sulfided MoO3/Al2O3 was proportional to the NO adsorption capacity. It is suggested that a homogeneous distribution of Mo oxide species is attained by an equilibrium adsorption technique. However, it was revealed that the surface area of the catalyst and Mo distribution were considerably modified by preparation parameters, such as drying processes, other than the surface area.