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 H₂ O₂ electrosynthesis technology, but it is still formidably challenging. It is reported that the low-coordinated structure of Pd sites in amorphous PdSe₂ nanoparticles (a-PdSe₂ NPs) can significantly boost the electrocatalytic synthesis of H₂ O₂ . Detailed investigations and theoretical calculations reveal that the disordered arrangement of Pd atoms in a-PdSe₂ 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 H₂ O₂ selectivity and productivity. Impressively, a-PdSe₂ NPs/C exhibits high H₂ O₂ selectivity over 90% in different pH electrolytes. H₂ O₂ productivities with ≈3245.7, 1725.5, and 2242.1 mmol g_Pd ^-1 h^-1 in 0.1 m KOH, 0.1 m HClO₄ , and 0.1 m Na₂ SO₄ can be achieved, respectively, in an H-cell electrolyzer, being a pH-universal catalyst for H₂ O₂ electrochemical synthesis. Furthermore, the produced H₂ O₂ can reach 1081.8 ppm in a three-phase flow cell reactor after 2 h enrichment in 0.1 m Na₂ SO₄ , showing the great potential of a-PdSe₂ NPs/C for practical H₂ O₂ electrosynthesis.