Enhanced Stabilization and Effective Utilization of Atomic Hydrogen on Pd–In Nanoparticles in a Flow-through Electrode

Abstract

Surface-adsorbed active species are intermediates with strong activities in heterogeneous catalytic reactions. Effective stabilization of these intermediates is crucial to improve the catalytic performance. Here, we demonstrated highly active bimetallic palladium-indium (Pd-In) nanoparticles (NPs) that can stabilize atomic H* on the surface and show efficient electrocatalytic reduction performance toward bromate. The optimal atomic ratio of Pd to In was investigated with the aim of efficient formation and strong stabilization of H*, thus facilitating the reduction and decontamination of carcinogenic bromate. Pd₂In₃ was the most active catalyst, with a high rate constant of 0.029 min^-1, whereas the rate constant for monometallic Pd NPs was only 0.009 min^-1. Density functional theory calculations suggest that Pd₂In₃ NPs decrease the work function and provide strong H* stabilization ability. By employing a flow-through electrode coated with Pd₂In₃ NPs to enhance the mass transport, the utilization of H* could be boosted and the reduction kinetics increased up to 7.5 times.