Process for preparing alkyl mercaptans in a multizone fixed bed reactor

A process for preparing alkyl mercaptans by a catalytic gas phase reaction of alkanols and hydrogen sulphide reactants over an alkali metal tungstate, said reactants being introduced in at least two successive reaction zones which contain different catalysts, such that an activity with respect to mercaptan formation of a first catalyst used in a first reaction zone is lower than an activity with respect to mercaptan formation of a second catalyst used in a second reaction zone or any subsequent reaction zones, and there is no feeding of the reactants between reaction zones.