Direct synthesis of hydrogen peroxide from hydrogen and oxygen over palladium catalysts supported on TiO2–ZrO2 mixed metal oxides

TiO2–ZrO2 (TZ-X (X = 0, 25, 50, 75, and 100)) supports were prepared by a co-precipitation method with a variation of ZrO2 content (X, mol%). Pd/TiO2–ZrO2 (Pd/TZ-X) catalysts prepared by an incipient wetness method were then applied to the direct synthesis of hydrogen peroxide from hydrogen and oxygen. It was revealed that both total acidity and surface acidity of Pd/TZ-X catalysts played an important role in determining the catalytic performance in the direct synthesis of hydrogen peroxide. Among the catalysts tested, Pd/TZ-75 catalyst with the largest total acidity and the largest surface acidity showed the highest yield for hydrogen peroxide.