EXAFS CHARACTERIZATION OF SUPPORTED NIOBIUM SULFIDE CATALYSTS

Niobium sulfide supported catalysts can reach activities higher than t hose of the classical MoS2 based catalysts. However, the nature of the support and the sulfurizing agent are of prime importance. Depending on the activation method or reaction test conditions, dispersed partic les of different entities such as NbS3, NbS2, Nb1-yS can be identified using the EXAFS technique. Moreover, the use of an asymmetric distanc e distribution model gives more reliable results than the classical ga ussian description, in the case of the highly disorded carbon-supporte d niobium sulfides.