A method for the manufacture of a sulfonated phenol for use as a cumene hydroperoxide decomposition catalyst can comprise: combining phenol and a sulfonating agent at a first temperature that is 1° C. to 15° C. higher than a melting temperature of the phenol, to form a reaction mixture at the first temperature; reducing the first temperature of the reaction mixture to a second temperature that is 10 to 40° C. lower than the first temperature; and forming the sulfonated phenol at the second temperature.