A new tetra-Zr(iv)-substituted polyoxotungstate aggregate

Area of Science:

• Inorganic Chemistry
• Materials Science
• Electrochemistry

Background:

• Tungstophosphates (TPs) are versatile polyoxometalates with diverse structures and applications.
• Developing novel TPs with tailored properties is crucial for advancing catalysis and materials science.
• The hydrothermal synthesis method offers a controlled approach for creating complex inorganic structures.

Purpose of the Study:

• To synthesize and characterize a novel tetra-Zr-substituted tungstophosphate.
• To investigate the structural features and electrochemical properties of the synthesized compound.
• To evaluate the catalytic activity of the new TP for reduction reactions.

Main Methods:

• Hydrothermal synthesis using [B-α-SbW9O33]9- building blocks, Zr4+ cations, and PO43- anions.
• Characterization techniques including IR spectroscopy, elemental analysis, TGA, PXRD, 31P NMR, and single-crystal X-ray diffraction.
• Electrochemical studies in Na2SO4 + H2SO4 supporting electrolyte to assess catalytic activity.

Main Results:

• A new toroidal tetra-Zr-substituted tungstophosphate, [H2N(CH3)2]6Na6H8{Zr2[SbP2W4(OH)2O21][α2-PW10O38]}2·50H2O (1), was successfully synthesized.
• The structure features two divacant [α2-PW10O38]11- units and two [SbP2W4(OH)2O21]7- fragments linked by Zr4+ cations, with PO4 replacing SbO3.
• Compound 1 exhibited catalytic activity for the reduction of H2O2 and BrO3-.

Conclusions:

• The successful synthesis of the novel toroidal TP demonstrates a new route for constructing complex tungstophosphate architectures.
• The unique structure of compound 1 contributes to its observed electrochemical catalytic properties.
• This study highlights the potential of Zr-substituted TPs as electrocatalysts for reduction reactions.