Design of yolk-shell structured PdSn@Pd@HCS nanocatalysts for efficient direct synthesis of H2O2

Abstract

The direct synthesis of hydrogen peroxide (DSHP) from hydrogen and oxygen is a green synthesis method with a high atomic economy. However, H2O2 selectivity and productivity remain a key challenge, the OO bonds are easily broken with supported Pd catalysts to produce water. Herein, we report the synthesis of bimetallic catalyst PdSn@Pd@HCS by adapting reversed-phase micellar and galvanic replacement reaction. The novel bimetallic yolk-shell structure catalysts exhibit excellent catalytic performance, the selectivity and productivity of H2O2 reaching 98% and 4899 mmol/gPd·h − 1, respectively. Theoretical calculations reveal that the presence of Sn inside the bimetallic alloy can enhance the ligand effect and optimize the electronic structure of the surface Pd atoms, weakening the adsorption ability of O2 molecules and inhibiting the dissociation of OO bonded species, resulting in the enhancement of H2O2 selectivity and productivity. This work provides the groundwork for bimetallic yolk-shell structure catalysts to achieve the efficient synthesis of H2O2.