Indirect Electrocatalysis S─N/S─S Bond Construction by Robust Polyoxometalate Based Foams

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Traditional direct electrocatalysis faces kinetic limitations in electron transfer.
• Indirect electrocatalysis offers a promising route to overcome these limitations for value-added chemical synthesis.
• Developing efficient catalysts is crucial for sustainable chemical production and industrial applications.

Purpose of the Study:

• To fabricate and evaluate di-copper-substituted phosphotungstate-based foams (PW10Cu2@CMC) for indirect electrocatalytic applications.
• To synthesize valuable S─N/S─S bond chemicals, such as sulfenamides and disulfides, for the rubber industry.
• To explore the simultaneous production of hydrogen gas alongside valuable chemicals.

Main Methods:

• Fabrication of phosphotungstate-based foams (PW10Cu2@CMC) with varying copper loadings (17-44 wt%).
• Indirect electrocatalytic conversion of organic raw materials focusing on S─H and N─H bond activation.
• Characterization of catalytic performance, including yields and hydrogen production rates.

Main Results:

• The optimal PW10Cu2@CMC (44 wt%) catalyst achieved high yields (up to 99%) for S─N/S─S bond formation.
• Efficient hydrogen production (≈50 µmol g⁻¹ h⁻¹) was observed concurrently with chemical synthesis.
• Demonstrated scalability with a batch production of ≈14.4 g and superior performance of products as rubber vulcanization accelerators.

Conclusions:

• Phosphotungstate-based foam catalysts offer a highly efficient system for indirect electrocatalytic synthesis.
• This approach enables the simultaneous production of valuable rubber additives and hydrogen fuel.
• The developed catalysis system opens new avenues for polyoxometalate-based foam catalysts in electrocatalysis.