It remains a challenge nowadays in the development of highly efficient catalysts for the direct synthesis of H 2 O 2 from H 2 and O 2 . In this work, we developed sulfur-doped carbon-supported Pd catalysts and systematically investigated sulfur effects on catalytic performances through various characterizations (transmission electron microscopy (TEM), N 2 adsorption−desorption, H 2 -temperature-programmed reduction (TPR)/temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), etc.). Results showed that sulfur species promoted the in situ formation of Pd nanoparticles and enhanced their dispersion on the supports. Due to the synergistic combination of active metal and support, the catalytic performance has been improved significantly in the direct synthesis of H 2 O 2 . The catalyst doped with the highest sulfur content showed the highest H 2 O 2 productivity of 7148 mmol g Pd −1 h −1 , which was nearly 4 times higher than the catalyst without sulfur doping.