The role of niobium in MCM-41 supported with Pt and Au—A comparative study of physicochemical and catalytic properties

This paper reviews a series of results, partly published recently, on niobosilicate mesoporous molecular sieves of MCM-41 type modified with noble metals (Pt, Au). Platinum is introduced to MCM-41 by impregnation technique, whereas gold is incorporated by two methods: during the synthesis by co-precipitation (COP) and by impregnation (IMP). Three fundamental features of the prepared materials have been considered: (i) texture/structure, (ii) noble metal state and dispersion, and (iii) catalytic activity. The latter has been tested in selective reduction of NO by propene, methanol oxidation and WGS process. The role of niobium, as well as the effect of the nature of noble metals and the preparation method on the physicochemical and catalytic properties of the final materials based on NbMCM-41 (in comparison with siliceous MCM-41) is demonstrated.