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

• Synthesis of group Vb metal oxides from alkoxide precursors.
• Nanostructuration, porosity and specific areas dependent on reaction conditions.
• Acid or basic conditions influence niobium and tantalum alkoxides in opposing ways.
• Modifications to surface chemistry of oxides affect catalytic performance.
• Highest surface area does not necessarily imply highest catalytic activity.

This study reveals how the textural properties of hierarchically porous group Vb 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 Vb 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.

The surface chemistry of hierarchically porous group Vb metal oxides as Pd catalyst supports leads to different activities in the catalytic oxidation of volatile organic compounds.Figure optionsDownload as PowerPoint slide