ABSTRACT

Co-Mo sulfide catalysts have been used in industry for hydrotreating of petroleum feedstocks. Synthesis of uniform Co-Mo binary sulfide clusters well-defined in structure and thermally stabilized on a support is desirable for better understanding of the nature of the catalysts. In the present review, successful preparations, using metal carbonyls as precursors, of Mo, Co and Co-Mo model sulfide clusters encaged in zeolite are summarized. The structure, location and catalytic properties of the clusters are described on the basis of XPS, XAFS, XRD, XRF, IR, HREM and adsorptions of benzene and NO. It is suggested that the host-guest interactions between the support and precursor molecules and sulfide clusters are crucial to the size and structure of the supported clusters.