The direct synthesis of H2O2 from H-2 and O-2 is an atom-efficient alternative to the anthraquinone autooxidation process. Herein, we report high-performance alumina supported palladium-tellurium bimetallic catalysts (Pd-Te/Al2O3) for the direct H2O2 synthesis using a semi-continuous process at 283 K and 0.1 MPa. By modifying the Pd catalyst with Te, the H2O2 productivity was markedly increased from 2017 to 2824 mmol h(-l)g(pd)(1). The role of Te in H(2)O(2 )synthesis was thoroughly studied by multiple techniques including in situ spectroscopies and density functional theory (DFT) calculations. The Pd monometallic sites, especially the high-energy step sites, have demonstrated to be highly active for the dissociation of O-2 and the subsequent formation of byproduct H2O. By blocking the high-energy step sites and forming Pd-Te bimetallic sites, Te plays a critical role in suppressing the side reactions and promoting H(2)O(2 )synthesis. This work provides inspiration for the rational design of bimetallic catalysts for H2O2 synthesis. (C) 2020 Elsevier Inc. All rights reserved.