H2O2 electrosynthesis activity and selectivity of Pd–Te nanoparticles with different surface compositions in acidic electrolyte

Abstract

The selective 2-electron oxygen reduction reaction (2e− ORR) has emerged as a promising alternative for H2O2 production to the traditional anthraquinone process, which has energy and environmental issues. H2O2 electrosynthesis in acidic electrolytes is more relevant to practical conditions but requires a much higher overpotential, where precious metal-based electrocatalysts have exhibited high efficiency for the 2e− ORR. The electrocatalytic activity and selectivity are critically affected by the surface composition of the constituent elements. However, such effects in acidic electrolytes have been rarely investigated for precious metal compounds. In this work, palladium–tellurium binary compounds with two different surface compositions were prepared, and their electrocatalytic properties were compared to reveal the structure–activity–selectivity correlations. It was found that the compound with a higher surface Te/Pd ratio exhibited higher H2O2 selectivity but lower activity due to the decreased numbers of Pd ensemble sites as well as surface Pd binding sites, respectively.