Spatial engineering of adjacent pair single-atom catalyst for reaction-pathway decoupling in advanced oxidation

Area of Science:

• Catalysis
• Environmental Chemistry
• Materials Science

Background:

• Single active sites in advanced oxidation processes (AOPs) limit efficiency due to competitive adsorption of pollutants and oxidants.
• Rational catalyst design is crucial for decoupling reaction pathways in AOPs.

Purpose of the Study:

• To design and investigate an adjacent pair single-atom catalyst (Co2/CN) for bifunctional catalysis in peroxymonosulfate (PMS)-based AOPs.
• To achieve efficient degradation of levofloxacin (LF) by decoupling PMS activation and pollutant degradation.

Main Methods:

• Synthesis of adjacent pair single-atom catalyst (Co2/CN).
• Performance evaluation using levofloxacin degradation in PMS-AOPs.
• Density Functional Theory (DFT) calculations to elucidate reaction mechanisms.

Main Results:

• The Co2/CN-PMS system achieved a levofloxacin degradation rate of 0.1 min⁻¹, significantly outperforming single-atom analogues (Co1/CN: 0.014 min⁻¹).
• DFT calculations revealed that adjacent Co sites facilitate co-adsorption of pollutant and PMS, decoupling activation and degradation.
• The catalyst design minimizes the migration distance of singlet oxygen for enhanced pollutant decomposition.

Conclusions:

• Adjacent pair single-atom catalysts offer bifunctional advantages in AOPs by enabling functional division between sites.
• This work presents a new design paradigm for paired single-atom catalysts, shifting from electronic modulation to functional division.
• The Co2/CN catalyst demonstrates superior performance for levofloxacin degradation in PMS-AOPs.