The effect of heat treatment on the performance and structure of carbon-supported Au-Pd catalysts for the direct synthesis of hydrogen peroxide

► Acid pre-treatment of carbon-supported AuPd catalysts switches off the non-selective reactions in direct synthesis of H2O2. ► The acid pre-treated samples all show superior activity to those prepared with the omission of this acid pre-treating stage. ► X-ray photoelectron spectroscopy and aberration-corrected scanning transmission electron microscopy show the effect of calcination on activity. ► The enhanced activity is associated with a higher surface concentration of palladium in the acid pre-treated samples which is principally present as Pd2+.