The oxidation of 2-methyl-naphthalene (2MN) to 2-methyl-1,4-naphthoquinone (2MNQ), vitamin K3 (menadione) was carried out over MoMCM-41 mesoporous molecular sieve catalyst. The typical reaction run was carried out using acetic acid as a solvent, hydrogen peroxide (H2O2) as an oxidant, in the temperature range of 60-120oC for 2-12 h. The liquid product selectivities to 2-methyl-1,4-naphthoquinone were 85, 80, 81 and 79 percent at 12, 69, 98 and ~99 percent conversions of 2MN for the molar ratio of 2MN:H2O2 equal to 1:2, 1:4, 1:6 and 1:7 respectively. The effect of the various parameters including reaction temperature, molar ratio of 2MN:H2O2, Si/Mo ratio, various catalysts, various solvents, the various molybdenum precursors and amount of catalyst were studied. The selectivity to benzaldehyde was ~99 percent at ~50 percent conversion of styrene over WMCM-41 mesoporous molecular sieve catalyst.
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