Selective and durable H₂O₂ electrosynthesis catalyst in acid by selenization induced straining and phasing.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalysts for acidic hydrogen peroxide (H₂O₂) electrosynthesis face challenges in selectivity and stability.
• Optimizing the oxygen reduction reaction (ORR) pathway is crucial for efficient H₂O₂ production.

Purpose of the Study:

• To develop efficient and stable electrocatalysts for H₂O₂ electrosynthesis in acidic media.
• To investigate the role of amorphous platinum-selenium (Pt-Se) shells on platinum (Pt) cores in manipulating the ORR pathway.

Main Methods:

• Constructing amorphous Pt-Se shells on crystalline Pt cores.
• Utilizing nanoparticles with optimized shell thickness for H₂O₂ production.
• Testing catalyst performance in a flow cell reactor for H₂O₂ concentration and productivity measurements.
• Evaluating the catalyst's efficacy in organic dye degradation.

Main Results:

• Pt-Se shells on Pt cores achieved over 95% selectivity for H₂O₂ production, suppressing decomposition.
• The catalyst maintained a current density of 250 mA cm⁻² for 400 hours.
• Achieved H₂O₂ concentration of 113.2 g L⁻¹ with a productivity of 4160.3 mmol gcat⁻¹ h⁻¹.
• Demonstrated effective organic dye degradation using the produced H₂O₂.

Conclusions:

• Amorphous Pt-Se shells on Pt cores effectively catalyze H₂O₂ electrosynthesis in acids by optimizing the ORR pathway.
• The Pt-Se shell enhances O₂ adsorption and OOH* binding, accelerating reaction kinetics and improving selectivity and stability.
• The selenization approach is generalizable for tuning the 2e⁻ ORR pathway in other noble metal catalysts.