Textural properties of supports and fresh catalysts were evaluated from N2 physisorption isotherms at -196 C using a Tristar 3000 instrument (Micromeritics). The sample was degassed under vacuum at 170 C overnight before the measurement so as to remove physisorbed water and other volatile contaminants. The specific surface area was determined by the Brunauer-Emmett-Teller (BET) method applied in a low range of relative pressure (P/P0) from 0.01 to 0.1, taking the presence of micropores into account . The total pore volume was estimated from the adsorption branch at P/P0 ~ 0.98, while the pore size distribution was obtained from the adsorption branch using the Barrett-Joyner-Halenda (BJH) method.