Industrial production of ether antiknock substances (e.g. ETBE or TAME) involves the use of catalysts based mainly on acidic ion-exchange resins. However, the use of such resins causes certain drawbacks leading to technological difficulties and for this reason the search for other catalysts suitable for the purpose is continued. Our studies were focused on the synthesis of tert-amyl methyl ether (TAME) in which different modified activated carbons were tested as catalysts. The modifications were undertaken to introduce sulphonic groups on the surface of activated carbon, as a result of reactions with such reagents as concentrated or fuming sulphuric acid, in situ generated diazonium salt of 4-aminobenzenesulphonic acid or sodium sulphide and hydrogen peroxide. For the sake of comparison, the activated carbon with P-containing and/or O-containing groups on the surface and the commercial catalyst Amberlyst-15 were used. The most effective method of -SO3H groups introduction has been proved to be the reaction of activated carbon with in situ generated diazonium salt. The majority of catalysts obtained were active in tertamyl methyl ether synthesis, however, significant differences in yields of TAME were observed, depending on the method of activated carbon modification. (C) 2015 Elsevier Ltd. All rights reserved.