Hierarchically nanostructured porous group V_b metal oxides from alkoxide precursors and their role in the catalytic remediation of VOCs

This study reveals how the textural properties of hierarchically porous group V_b metal oxides, prepared via a spontaneous auto-formation process, can strongly depend upon the pH of the reaction media, with an acidic media increasing the specific surface of Nb₂O₅ whereas a basic medium results in the highest specific surface for Ta₂O₅. Catalytic oxidation of toluene over Pd loaded hierarchically porous group V_b systems, and the supports alone, has shown that supports synthesised at pH 6 are the most active, despite having lower specific surfaces, thus implying modifications to the surface chemistry in the presence of H⁺ or OH^- can affect the overall performance of the supported catalytic system.