Low-Coordinated Pd Site within Amorphous Palladium Selenide for Active, Selective and Stable H 2 O 2 Electrosynthesis.

The development of high-performance catalysts with high activity, selectivity and stability are essential for the practical applications of H 2 O 2 electrosynthesis technology, but it is still formidably challenging. We report that the low-coordinated structure of Pd sites in amorphous PdSe 2 nanoparticles (a-PdSe 2 NPs) can significantly boost the electrocatalytic synthesis of H 2 O 2 . Detailed investigations and theoretical calculations reveal that the disordered arrangement of Pd atoms in a-PdSe 2 NPs can promote the activity, while the Pd sites with low-coordinated environment can optimize the adsorption towards oxygenated intermediate and suppress the cleavage of O-O bond, leading to a significant enhancement in both the H 2 O 2 selectivity and productivity. Impressively, a-PdSe 2 NPs/C exhibits high H 2 O 2 selectivity over 90% in different pH electrolytes. H 2 O 2 productivities with ca. 3245.7, 1725.5, and 2242.1 mmol g Pd -1  h -1 in 0.1 M KOH, 0.1 M HClO 4 , and 0.1 M Na 2 SO 4 can be achieved, respectively, in an H-cell electrolyzer, being a pH-universal catalyst for H 2 O 2 electrochemical synthesis. Furthermore, the produced H 2 O 2 can reach 1081.8 ppm in a three-phase flow cell reactor after 2 h enrichment in 0.1 M Na 2 SO 4 , showing the great potential of a-PdSe 2 NPs/C for practical H 2 O 2 electrosynthesis. This article is protected by copyright. All rights reserved.