Non-Local Electronic Perturbation at Low-Coordinated Ru Sites Boosts N₂ Photoreduction

Area of Science:

• Heterogeneous Photocatalysis
• Materials Science
• Catalysis

Background:

• Atomic-level control of coordination environments in single-atom catalysts (SACs) is crucial for heterogeneous photocatalysis.
• Current methods often focus on first-shell modifications, limiting electronic tuning capabilities.

Purpose of the Study:

• To develop a second-shell engineering strategy for single-atom catalysts (SACs).
• To investigate the impact of incorporating oxygen into the secondary coordination sphere of Ru-N2 sites.
• To enhance the catalytic activity for ammonia evolution.

Main Methods:

• Engineered Ru-N2 sites by inserting oxygen into the second coordination sphere (Ru-O-CN).
• Utilized a remote electron-pumping mechanism via a C-O-N bridging network.
• Investigated electronic perturbations and π-back-donation interactions.

Main Results:

• Achieved a significant reduction in the rate-determining step barrier for N2 reduction (from 1.034 to 0.822 eV).
• Observed a 2.64-fold enhancement in ammonia evolution rate compared to Ru-CN catalysts.
• Demonstrated a 150-fold improvement over pristine g-C3N4 catalysts, reaching 767.52 µmol·g⁻¹·h⁻¹.

Conclusions:

• Second-shell engineering via heteroatom doping offers an effective strategy for tuning SAC electronic structures.
• Non-local electronic perturbation is a viable approach to enhance catalytic performance.
• This method provides a new avenue for designing advanced single-atom catalysts.