Effect of nanoporous ZrO_2 crystal size on the surface sulphur capacity and performance of sulfated zirconia as an acidic catalytic material

摘要

Three sulfated zirconia materials were prepared with crystal size of tetragonal ZrO_2 of 2.5-15 ran and sulphur content corresponding to the full surface sulphur capacity of this phase. They were synthesized by sulfation of amorphous Zr hydroxide precipitated in presence and absence of block-copolymer non-ionic surfactant and of tetragonal zirconia preformed inside mesopores of SBA-15 silica matrix. It was demonstrated that while the crystal size of tetragonal ZrO_2 phase and its surface area determine the maximal amount of sulfate ions and concentration of acid sites in the material the acidity strength and catalytic activity in three different reactions is a function of preparation history.