A rare polyoxometalate cluster [NiW₁₂O₄₄]^14- based solid as a pre-catalyst for efficient and long-term oxygen...

Area of Science:

• Inorganic Chemistry
• Materials Science
• Electrochemistry

Background:

• Polyoxometalates (POMs) are diverse metal oxide anionic clusters with significant potential.
• The synthesis of novel POM structures, like the NiW12O44 cluster, is crucial for expanding their applications.

Purpose of the Study:

• To report the synthesis and characterization of a new POM solid, (C5H7N2)6[NiW12O44] (PS-78).
• To investigate the electrocatalytic activity of PS-78 for the oxygen evolution reaction (OER) in alkaline media.
• To elucidate the active species and mechanism involved in the OER catalyzed by PS-78.

Main Methods:

• Synthesis and characterization of the (C5H7N2)6[NiW12O44] solid.
• Electrochemical evaluation of the material as an oxygen evolution pre-catalyst.
• Mechanistic studies using *in situ* generated species.

Main Results:

• A novel [NiW12O44]14- cluster was synthesized, bridging existing POM topologies.
• PS-78 demonstrated efficient and sustained OER activity with an overpotential of 347 mV at 10 mA cm-2.
• Long-term stability of up to 96 hours was achieved for the pre-catalyst.
• *In situ* generated NiO and WOx (x=1, 2) species were identified as the active sites for OER.

Conclusions:

• The synthesized (C5H7N2)6[NiW12O44] solid represents a new POM topology with valuable catalytic properties.
• POMs show great promise as efficient pre-catalysts for oxygen evolution reactions in alkaline electrolytes.
• This work encourages further exploration of POMs for advanced electrocatalytic applications.