The catalytic transformations of 4-tert-butylphenol in hydrogen peroxide solutions were investigated in the presence of crystalline and amorphous titanosilicates and titanium oxide. The TS-1 microporous crystalline titanosilicate was shown to exhibit low activity in the 4-tert-butylphenol transformation due to the steric limitations on the diffusion of the substrate molecules towards catalytic active centers. Mesoporous amorphous titanosilicates were more selective in the 4-tert-butylcatechol formation than the titanium oxide. The selectivity to 4-tert-butylcatechol in the presence of the TiO2 did not exceed 20 mol%. The maximum 53 mol% selectivity value to 4-tert-butylcatechol was shown to occur over the amorphous mesoporous titanosilicate containing 1.9 wt% of Ti, the 4-tert-butylphenol conversion value being equal to 42 mol%.