Low‐Coordinated Pd Site within Amorphous Palladium Selenide for Active, Selective, and Stable H2O2 Electrosynthesis

Abstract 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. It is reported 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 toward 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 ≈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.