Interfacial engineering passivation-resistant NiMoO₄-Ru heterointerface with modulated electronic structure for...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Sulfide oxidation reaction (SOR) is crucial for energy-saving hydrogen production.
• Sulfur passivation of electrocatalysts hinders practical SOR implementation due to over-binding of sulfur intermediates.

Purpose of the Study:

• To develop a strategy to mitigate sulfur passivation in electrocatalysts for SOR.
• To engineer a novel heterostructure to enhance catalyst performance and stability.

Main Methods:

• Constructed a three-dimensional Ru/NiMoO4 heterostructure on nickel foam (Ru/NiMoO4-R/NF).
• Utilized X-ray photoelectron spectroscopy, X-ray absorption fine structure, and density functional theory (DFT) calculations to analyze interfacial electronic properties.
• Employed in-situ Raman spectroscopy to monitor reaction intermediates and surface passivation.

Main Results:

• Demonstrated strong electronic coupling at the Ru/NiMoO4 heterointerface, inducing charge transfer and creating electron-deficient Ru sites.
• Achieved significantly weakened adsorption of sulfur species, effectively suppressing surface passivation.
• The Ru/NiMoO4-R/NF electrode showed excellent SOR activity (0.338 V at 100 mA cm⁻²) and stability (>360 h).
• The integrated system achieved high current density (720 mA cm⁻²) at a low cell voltage (0.94 V) with 160-h stability during overall sulfide electrolysis.

Conclusions:

• Interface engineering via electronic modulation is an effective strategy to overcome noble-metal catalyst passivation in SOR.
• The developed Ru/NiMoO4 heterostructure offers a promising pathway for efficient and stable hydrogen production through SOR.