Assembly of Heteropoly Acid Nanoparticles in SBA-15 and Its Performance as an Acid Catalyst

Keggin‐type 12‐tungstophosphoric acid (TPA) nanocrystals have been assembled inside the pores of mesoporous silica through a vacuum impregnation method by using large‐pore SBA‐15 as a nanoreactor. The product was characterized by Brunauer–Emmet–Teller particle size distribution (BET‐PSD), NMR and FT‐IR spectroscopy, X‐ray diffraction (XRD), tranmsission electron microscopy (TEM), differential thermal analysis (DTA) and FT‐IR of adsorbed pyridine. The experimental results illustrate that the TPA nanocrystals are excellent Brønsted acid catalytic materials at room temperature. Nanoreactors! Keggin‐type 12‐tungstophosphoric acid nanocrystals have been assembled inside the mesopores of SBA‐15 as a nanoreactor through a vacuum impregnation method (see scheme) and are demonstrated to be excellent Brønsted acid catalytic materials.