METHOD OF SO-INTO-SO CONVERSION CATALYST Russian patent published in 1999 - IPC

FIELD: oxidation catalysts. SUBSTANCE: hydrosilica gel is prepared by precipitation with sulfuric acid and thus obtained suspension is supplemented by powdered silica gel carrier, after which impregnation with solutions of active components is effected, followed by drying of pulp, molding, and heat treatment. Invention is distinguished by that precipitation of hydrosilica gel is conducted under unsteady condition by uniformly pouring sulfuric acid to pulp containing dissolved silica, pH of pulp being varied from initial value not exceeding 13.5 to final value at least 5.5 over the time period 5 to 120 min and suspension obtained being supplemented by carrier with particle size not exceeding 1 mm and specific surface value at least 10 sq. m/g. Weight ratio of additional carrier to sum of precipitated hydrosilica gel and additional carrier ranges from 0.05 to 0.85 on conversion to solid materials. EFFECT: stabilized catalyst activity at 420 C when resins are temporarily in reaction mixture are cooled to 360 C. 12 ex