Intrinsic Activity Identification of Noble Metal Single‐Sites for Electrocatalytic Chlorine Evolution
Quan Li, Xin Zhao, Li‐Ming Yang, Bo You, Bao Yu Xia
Abstract
Abstract Single‐atom catalysts with maximal atom‐utilization have emerged as promising alternatives for chlorine evolution reaction (CER) toward valuable Cl 2 production. However, understanding their intrinsic CER activity has so far been plagued due to the lack of well‐defined atomic structure controlling. Herein, we prepare and identify a series of atomically dispersed noble metals (e.g., Pt, Ir, Ru) in nitrogen‐doped nanocarbons (M 1 −N−C) with an identical M−N 4 moiety, which allows objective activity evaluation. Electrochemical experiments, operando Raman spectroscopy, and quasi‐in situ electron paramagnetic resonance spectroscopy analyses collectively reveal that all the three M 1 −N−C proceed the CER via a direct Cl‐mediated Vomer‐Heyrovský mechanism with reactivity following the trend of Pt 1 −N−C>Ir 1 −N−C>Ru 1 −N−C. Density functional theory (DFT) calculations reveal that this activity trend is governed by the binding strength of Cl*−Cl intermediate (ΔG Cl*−Cl ) on M−N 4 sites (Pt<Ir<Ru) featuring distinct d‐band centers, providing a reliable thermodynamic descriptor for rational design of single metal sites toward Cl 2 electrosynthesis.