Confinement boosts CO oxidation on an Ni atom embedded inside boron nitride nanotubes

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Heterogeneous catalysis research traditionally focuses on metal particles on substrate surfaces.
• Studies on metallic nanoparticles within nanotube interiors remain scarce.
• Boron nitride nanotubes (BNNTs) offer unique structural properties for catalytic applications.

Purpose of the Study:

• To investigate the catalytic activity of a single nickel atom confined within a nitrogen vacancy on the interior surface of BNNTs for CO oxidation.
• To compare the catalytic performance of interior- vs. exterior-supported nickel nanoparticles.
• To explore the influence of nanotube structure on catalytic efficiency.

Main Methods:

• Utilizing first-principles calculations based on density functional theory (DFT).
• Investigating the Eley-Rideal mechanism for CO oxidation.
• Analyzing energy barriers for the rate-determining step across different BNNT structures (e.g., BNNT(5,5), BNNT(6,6), BNNT(7,7)).

Main Results:

• A single nickel atom confined inside a BNNT exhibits significantly higher catalytic activity for CO oxidation compared to nickel on the exterior surface.
• Low energy barriers for the rate-determining step were calculated: 0.39 eV for BNNT(5,5), 0.29 eV for BNNT(6,6), and 0.33 eV for BNNT(7,7).
• The confinement effect within the nanotube interior is crucial for enhanced catalytic performance.

Conclusions:

• Confinement of single metal atoms within nanotube interiors is a promising strategy for developing highly active heterogeneous catalysts.
• The interior surface of BNNTs provides a unique environment that boosts catalytic efficiency for CO oxidation.
• This study demonstrates the significant merit of confinement in optimizing catalytic processes at the nanoscale.