The Laccase-Like Mechanism in Peroxymonosulfate-Based Oxidation System for Water Decontamination: Dual-Substrate...

Area of Science:

• Environmental Science
• Catalysis
• Oxidation Processes

Background:

• Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) are crucial for pollutant degradation.
• Enzymes like laccase offer highly efficient catalytic mechanisms.
• Developing effective catalysts for PMS-AOPs often relies on empirical strategies.

Purpose of the Study:

• To investigate the oxidation mechanism of direct electron transfer (DET)-dominated PMS-AOPs.
• To compare the mechanism of PMS-AOPs with that of laccase.
• To explore the potential of laccase-mimetic approaches for catalyst design.

Main Methods:

• Utilized a detachable catalyst (manganese phthalocyanine/carbon nanotubes - MnPc/CNT).
• Employed galvanic cell experiments and density functional theory (DFT) calculations.
• Conducted comparative studies using various metal phthalocyanine/CNT catalysts (Fe, Co, Ni, Cu, Zn).

Main Results:

• MnPc/CNT demonstrated efficient phenol (PE) removal via DET and polymerization.
• The catalyst exhibited dual-substrate activation of both PE and PMS, a novel finding in PMS-AOPs.
• Catalyst performance correlated with open circuit potentials, with MnPc/CNT, FePc/CNT, and CoPc/CNT showing superior efficiency.

Conclusions:

• DET-dominated PMS-AOPs share a laccase-like mechanism, including dual-substrate activation and pollutant polymerization.
• The laccase-mimetic approach offers a promising strategy for designing high-performance catalysts for PMS-AOPs.
• Understanding this mechanism can guide future catalyst development beyond empirical methods.