Kirkendall Effect-Driven Interface Engineering Facilitates Water Dissociation for Dual-Site H₂O₂ Electrosynthesis...

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Direct integration of renewable energy into H2O2 electrosynthesis is key to reducing energy losses and costs.
• Intermittency of renewable sources necessitates dual-site catalysts for efficient two-electron oxygen reduction (2e- ORR) and water oxidation (2e- WOR).

Purpose of the Study:

• To develop a novel catalyst for efficient H2O2 electrosynthesis directly powered by intermittent renewable energy.
• To engineer catalyst interfaces using the Kirkendall effect for enhanced catalytic activity.

Main Methods:

• Utilized the Kirkendall effect to engineer interfaces and construct a NiZnOx-C catalyst with exposed (100) facets.
• Investigated the role of hetero-cluster NiOx in inducing oxygen vacancies and built-in electric fields for water activation.
• Employed a continuous-flow reactor for stable catalyst operation under simulated AC and DC currents.

Main Results:

• Achieved rapid synthesis of high-concentration H2O2 (33987 mg L-1) via cathode 2e- ORR.
• Demonstrated stable 2e- ORR/WOR coupling for 4 hours.
• Attained a total Faradaic efficiency of 150.9% under direct current.

Conclusions:

• The NiZnOx-C catalyst, engineered via the Kirkendall effect, enables efficient H2O2 electrosynthesis.
• The catalyst facilitates direct integration of intermittent renewable energy sources into H2O2 production systems.
• Interface engineering provides a viable strategy for developing advanced electrocatalysts.