Platinum-aluminum electrocatalysts supported on carbon black were investigated for electrogenerative sulfur dioxide (SO2) oxidation in hybrid type, liquid-phase SO2/O-2 cells. Incorporation of aluminum with platinum electrocatalysts on carbon resulted in an electrocatalytic activity increase for SO2 oxidation over the whole investigated range (1-30 at % aluminum). Significant synergistic effect from aluminum was observed when even a small amount, as little as 1 at %, was incorporated in the platinum. A maximum 68% improvement was obtained when 10 at % aluminum was incorporated in the platinum. Results of an ESCA study and electrochemical platinum surface area measurement supported the hypothesis of an electronic interaction between platinum and aluminum.