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

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 characte rizations and catalytic tests. It was found that the surface area of t he support was the most predominant preparation parameter for the disp ersion of Mo oxide species; the dispersion increased as the surface ar ea of the support increased. The formation of crystalline MoO3 was obs erved at a surface Mo concentration higher than 3.2 Mo nm(-2). With su lfided MoO3/Al2O3, it was established that the dispersion of Mo sulfid e species increased with increasing surface area of the support and wa s in proportion to that of Mo oxide precursor species. The hydrodesulf urization activity of sulfided MoO3/Al2O3 was proportional to the NO a dsorption 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, suc h as drying processes, other than the surface area. (C) 1998 Elsevier Science B.V. All rights reserved.