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

The development of high-performance catalysts with high activity, selectivity, and stability are essential for the practical applications of H O electrosynthesis technology, but it is still formidably challenging. It is reported that the low-coordinated structure of Pd sites in amorphous PdSe nanoparticles (a-PdSe NPs) can significantly boost the electrocatalytic synthesis of H O . Detailed investigations and theoretical calculations reveal that the disordered arrangement of Pd atoms in a-PdSe 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 O selectivity and productivity. Impressively, a-PdSe NPs/C exhibits high H O selectivity over 90% in different pH electrolytes. H O productivities with ≈3245.7, 1725.5, and 2242.1 mmol g  h in 0.1 m KOH, 0.1 m HClO , and 0.1 m Na SO can be achieved, respectively, in an H-cell electrolyzer, being a pH-universal catalyst for H O electrochemical synthesis. Furthermore, the produced H O can reach 1081.8 ppm in a three-phase flow cell reactor after 2 h enrichment in 0.1 m Na SO , showing the great potential of a-PdSe NPs/C for practical H O electrosynthesis.