EXAFS CHARACTERIZATION AND CATALYTIC PROPERTIES OF SUPPORTED NIOBIUM SULFIDE CATALYSTS

Niobium sulphide supported catalysts can reach catalytic activities hi gher than those of classical MoS2 based catalysts. However, the nature of the support and the sulfurizing agent are of prime importance. Dep ending on the preparation and the activation method, dispersed particl es of different entities such as NbS3, NbS2 and Nb1-yS can be identifi ed using the EXAFS technique. In this work, relations between structur al arrangement and catalytic activity are discussed; species with cati on clustering are shown to be particularly active.