The effect of zirconium and niobium oxidic species on platinum dispersion in 1%Pt/Nb,Zr-containing MCM-41

Platinum was deposited on MCM-41 mesoporous supports that contained niobium and/or zirconium introduced either at the stage of mesoporous material synthesis or after synthesis by impregnation. It has been found that zirconium introduced during synthesis of MCM-41, influenced particle size of the material to a considerable extent and this, in turn, resulted in quite a high dispersion of platinum on the support. Such an effect was not observed in the case of niobiosilicate material. Niobium affected dispersion, when it was introduced to silicate MCM-41 by impregnation. Niobium oxidic species formed on mesoporous material surface, due to their strong interaction with platinum, prevented from sintering of the latter during reduction, thus increasing platinum dispersion.