Mesoporous Cr₂O₃–Phosphomolybdic Acid Solid Solution Frameworks with High Catalytic Activity

Mesoporous nanocomposite frameworks of chromium(III) oxide and 12-phosphomolybdic acid (PMA) compounds were prepared via a “nanocasting” method, using mesoporous silica SBA-15 as the template. Small-angle X-ray scattering, transmission electron microscopy, and nitrogen physisorption characterizations indicate that these materials possess a well-ordered hexagonal mesostructure with high content of PMA clusters (up to 63 wt %) and large internal surface area (up to 165 m 2 g –1 ). The Keggin clusters are incorporated intact into the mesoporous walls forming a Cr 2 O 3 –PMA solid-solution structure, according to the X-ray diffraction and X-ray photoelectron and ultraviolet–visible light (UV/vis) spectroscopy. These Cr 2 O 3 –PMA nanocomposites demonstrated strong potential for green oxidative processes, exhibiting high catalytic activity and durability in oxidation of 1-phenylethanol using H 2 O 2 as an oxidant.