Liquid phase di-tert-butylperoxide synthesis from the condensation reaction between tert-butyl alcohol and tert-butylhydroperoxide over microporous H-beta zeolites, having Si/Al molar ratios ranging from 11.5 to 120, has been investigated. With increasing Al content or in other words the acidity of H-beta zeolite, the catalytic activity is increased and passes through maxima; however, the selectivity for di-tert-butylperoxide is decreased initially to a small extent and then maintain almost the same level. Among the different M-containing beta zeolites, the catalyst with a SUM molar ratio of 40 shows the best performance in the above condensation reaction. Additionally, when compared with other commonly used heterogeneous acidic microporous zeolites (H-ZSM-5, H-mordenite, H-Y, H-MCM-22) and mesoporous solids (Al-MCM-41, Al:SBA-15) having similar Si/Al ratios but different pore structures, the catalytic activity of the H-beta zeolite in the di-tert-butylperoxide synthesis process is found to be much higher. (c) 2006 Elsevier B.V. All rights reserved.