ALUMINA-SUPPORTED SULFIDED CATALYSTS .2. A HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY

The surface morphology of Ni-Mo/Al2O3 and Co-Mo/Al2O3 catalysts prepar ed both from metal-complexes and by a conventional impregnation method is studied by high-resolution transmission electron microscopy. It is shown that the active component of these catalysts is crystallized in to structures typical of sulfide species in Mo/Al2O3 catalysts. Indivi dual layered species of the active component are attached to the surfa ce either by a side face or by a basal plane. The reasons for the stab ilization of highly dispersed sulfide species in the absence of their epitaxial interaction with the support are discussed.