Pd17Se15-Pd3B nanocoral electrocatalyst for selective oxygen reduction to hydrogen peroxide in near-neutral electrolyte

Abstract

An efficient approach to shift the reaction pathway from the 4-electron oxygen reduction reaction (4e− ORR) to the 2e− ORR is by fabricating precious metal compounds. The selectivity of the latter reaction is critical for the efficiency of H2O2 electrosynthesis technology. Herein, we demonstrate the high 2e− ORR activity and selectivity of a nanocoral-shaped Pd-based compound comprising Pd17Se15 and Pd3B mixed phases (Pd-Se-B NC). In contrast, metallic Pd exhibited nearly 100% 4e− ORR selectivity. The mass activity of Pd-Se-B NC for H2O2 generation was ~37-fold higher than that of the Pd black catalyst. Importantly, Pd-Se-B NC exhibited one of the highest H2O2 electrosynthesis activities in neutral media reported to date. The chemical states and composition of the Pd-Se-B NC remained almost intact even after sustained electrocatalysis.