A Surface-Strained and Geometry-Tailored Nanoreactor that Promotes Ammonia Electrosynthesis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen fixation is crucial for sustainable ammonia production.
• Developing efficient catalysts for nitrogen reduction reaction (NRR) remains a significant challenge.
• Titanium dioxide (TiO2) is a promising material, but its performance in NRR needs enhancement.

Purpose of the Study:

• To design and investigate a surface-strained and geometry-optimized TiO2 nanoreactor for enhanced electrocatalytic nitrogen fixation.
• To understand the role of lattice strain and nanostructure in improving NRR performance.
• To achieve high ammonia yield and selectivity under ambient conditions.

Main Methods:

• Fabrication of TiO2 nanoreactors with tailored surface strain and nanotubular geometry.
• Electrocatalytic performance evaluation for nitrogen reduction reaction (NRR).
• Experimental and theoretical studies (e.g., DFT calculations) to elucidate reaction mechanisms and active sites.

Main Results:

• The engineered TiO2 nanoreactor exhibited enhanced ammonia (NH3) production.
• Achieved an NH3 yield rate of 5.50 μg h⁻¹ cm⁻² and a faradaic efficiency of 26% under ambient aqueous conditions.
• Experimental and theoretical evidence confirmed the presence of strained Ti³⁺ sites facilitating N2 activation and NH3 production.

Conclusions:

• Surface strain and optimized geometry in TiO2 nanoreactors significantly improve electrocatalytic nitrogen fixation.
• The strained Ti³⁺ sites provide a more favorable pathway for N2 activation and selective NH3 synthesis.
• This work offers a new strategy for designing advanced nanoreactors for renewable energy catalysis and electrosynthesis.