Group V metal substitution in silicate model zeolites: In search for the active site

Group V substituted zeolites were characterized using periodic DFT. It is found that the group V sites in zeolite materials become more hydrophobic and less reducible descending the column of the Period Table. The stable site with TO group for T = V, transforms into a site with T–OH group for T = Ta. For niobium both sites (Nb–OH and NbO) are in competition with each other. The presence of Lewis acid base pairs is predicted in Nb and Ta dehydrated zeolites.