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

Authors: Zhiyong Yu, Shengyao Lv, Qing Yao, Nan Fang, Yong Xu*, Qi Shao, Chih-Wen Pao, Jyh-Fu Lee, Guoliang Li, Liming Yang*, Xiaoqing Huang*

Abstract: The development of high-performance catalysts with high activity, selectivity and stability are essential for the practical applications of H₂O₂ electrosynthesis technology, but it is still formidably challenging. We report that the low-coordinated structure of Pd sites in amorphous PdSe₂ nanoparticles (a-PdSe₂ NPs) can significantly boost the electrocatalytic synthesis of H₂O₂. 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 towards oxygenated intermediate and suppress the cleavage of O–O bond, leading to a significant enhancement in both the H₂O₂ selectivity and productivity. Impressively, a-PdSe₂ NPs/C exhibits high H₂O₂ selectivity over 90% in different pH electrolytes. H₂O₂ productivities with ca. 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 Na₂SO₄ can be achieved, respectively, in an H-cell electrolyzer, being a pH-universal catalyst for H₂O₂ electrochemical synthesis. Furthermore, the produced H₂O₂ can reach 1081.8 ppm in a three-phase flow cell reactor after 2 h enrichment in 0.1 M Na₂SO₄, showing the great potential of a-PdSe₂ NPs/C for practical H₂O₂ electrosynthesis.

Full-Link: https://onlinelibrary.wiley.com/doi/10.1002/adma.202208101