Reaction Mechanism

High-Energy SRR Inorganic Free Radical Clusters:
Activation of the radical source with water generates diverse and abundant inorganic free radical clusters (collectively referred to as the SRR Free Radical System), primarily including oxygenated acid radicals (sulfate radicals (SO?·?), carbonate radicals (CO?·?), phosphate radicals (H?PO?·, HPO?·, PO?·²?)), hydroxyl radicals (·OH), chlorine radicals (·Cl), hydroperoxyl radicals (HO?·), superoxide anion radicals (O?·?), and singlet oxygen (¹O?). With a standard oxidation potential of E? = 2.5–3.1 eV, this high-energy potential enables the mineralization of nearly all industrial waste gases, volatile organic compounds (VOCs), and odorous substances.
 

Principle of Chain Reaction between SRR Free Radical Clusters and Organic Pollutants (VOCs)
(Illustrated using the sulfate radical (SO?·?) as an example)

The SRR free radical clusters initiate efficient chain reactions with organic pollutants through three primary mechanisms:

1. Hydrogen Atom Abstraction (HAA)

• Primary Targets: Saturated organic compounds including alcohols, alkanes, ethers, and esters

• Reaction Mechanism:
  SO?·? + R-H → HSO?? + R·
  The sulfate radical abstracts a hydrogen atom from the organic substrate, generating a carbon-centered radical (R·) that subsequently undergoes further oxidation.

2. Addition Reaction

• Primary Targets: Unsaturated compounds containing C=C bonds, particularly alkenes

• Reaction Mechanism:
  SO?·? + H?C=CH-R → ·O?S-CH?-CH·-R
  The radical adds across the electron-rich double bond, forming a carbon-centered radical adduct that rapidly undergoes subsequent degradation.

3. Electron Transfer Reaction

• Primary Targets: Aromatic compounds and other electron-rich molecules

• Reaction Mechanism:
  SO?·? + Ar-H → SO?²? + Ar-H·?
  Single-electron transfer generates radical cations that initiate ring-opening and mineralization pathways.

Chain Propagation Characteristics:
The carbon-centered radicals (R·) generated through these mechanisms react rapidly with dissolved oxygen or other radical species, propagating a continuous chain reaction that ultimately mineralizes VOCs to CO?, H?O, and inorganic salts. This multi-pathway mechanism ensures effective degradation of diverse VOC structures across varying concentration ranges.