Study of the\nBHT Oxidation Mechanism Coupling Theory\nand Experiment

In the present work, the oxidation mechanism of di-<i>t</i>-butyl-hydroxytoluene (BHT) was studied in an aqueous medium\nthrough\ndifferent approaches to have a thorough vision of the physical chemistry:\nexperiments with cyclic voltammetry (CV), quantum chemical calculations,\nand simulations of CV. Calculations of thermodynamic parameters, such\nas p<i>K</i><sub>a</sub> and standard oxidation potential\n(<i>E</i><sub>ox</sub>°), were used to analyze and\nrationalize the CV experiments. Subsequently, different pathways of\nthe mechanism were constructed, and the most thermodynamically favorable\none was selected. Numerical simulations were then used to model this\nmechanism and compare it with the experimental data. The results show\nthat the oxidation process is due to the coupled loss of an electron\nand a proton in the first instance, followed by an irreversible second\nelectron-transfer process without loss of protons, mainly due to the\nadsorption of the products of the first oxidation on the electrode\nsurface. The effect of different pH values on this oxidative mechanism\nwas also analyzed, with alkaline pH of 12 as a medium where changes\nin reactivity were observed as the appearance of a new peak in the\nsecond voltammetric sweep, the interpretation of this peak is also\nprovided.