Study of the BHT Oxidation Mechanism Coupling Theory and Experiment

Area of Science:

• Electrochemistry
• Physical Chemistry
• Computational Chemistry

Background:

• Di-t-butyl-hydroxytoluene (BHT) is an antioxidant with a complex oxidation mechanism.
• Understanding BHT's electrochemical behavior is crucial for its application and degradation studies.

Purpose of the Study:

• To elucidate the oxidation mechanism of BHT in an aqueous medium.
• To correlate experimental electrochemical data with theoretical calculations and simulations.

Main Methods:

• Cyclic voltammetry (CV) experiments were performed.
• Quantum chemical calculations were employed to determine thermodynamic parameters (pKa, Eox°).
• Numerical simulations were used to model and validate the proposed oxidation mechanism.

Main Results:

• The primary oxidation step involves coupled electron and proton loss.
• A subsequent irreversible second electron-transfer process occurs, influenced by product adsorption.
• BHT oxidation mechanism exhibits significant pH dependence, with unique reactivity observed at alkaline pH 12.

Conclusions:

• The study provides a comprehensive understanding of BHT's electrochemical oxidation pathway.
• The findings highlight the role of coupled electron-proton transfer and product adsorption.
• The pH-dependent nature of the mechanism offers insights into BHT's behavior in different aqueous environments.