Engineering non-interfacial hydrogen spillover in a Ni₁₇W₃-WO₂ heterostructure.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Hydrogen spillover is crucial for hydrogen evolution reaction (HER) catalysts, but conventional methods face kinetic bottlenecks due to interfacial proton transfer.
• Existing HER catalysts often exhibit energy barriers associated with proton transfer across different material phases.

Purpose of the Study:

• To introduce a non-interfacial hydrogen spillover mechanism to overcome limitations in conventional HER catalysts.
• To engineer a Ni17W3-WO2 heterostructure that facilitates efficient proton desorption and hydrogen production.

Main Methods:

• Fabrication of a Ni17W3-WO2 heterostructure with a built-in strain gradient and directional electron transfer.
• Experimental and theoretical analyses to investigate the hydrogen spillover mechanism and interfacial properties.
• Electrochemical testing to evaluate catalyst performance, including overpotential, stability, and Faradaic efficiency.

Main Results:

• Demonstrated a non-interfacial hydrogen spillover mechanism, circumventing cross-phase migration and interfacial barriers.
• Achieved a low overpotential of 21 mV at 10 mA cm-2 in sulfuric acid.
• Exhibited excellent stability (>1500 hours at 500 mA cm-2) and high Faradaic efficiency (98.65%).

Conclusions:

• Tailored heterostructures can effectively bypass interfacial bottlenecks in hydrogen spillover.
• The developed Ni17W3-WO2 catalyst offers a promising pathway for efficient, non-precious electrocatalysts for sustainable hydrogen production.