The selective oxidation of 2,3,6-trimethylphenol (TMP) is of great importance for the preparation of 2,3,5-trimethyl-pbenzoquinone (TMBQ), a key intermediate in the production of Vitamin E. Various oxidant/catalyst, such as O2 or H2O2/CuCl2 (especially with various co-catalysts) have been employed in this oxidation process on the industrial scale. However, the main drawback of the above-mention...