General Efficacy of Atomically Dispersed Pt Catalysts for the Chlorine Evolution Reaction: Potential-Dependent Switching of the Kinetics and Mechanism

The electrochemical chlorine evolution reaction (CER) is a key anodic reaction in the chlor-alkali process for Cl 2 production, on-site generation of ClO –, and Cl 2 -mediated electrosynthesis. Although Ru-based mixed metal oxides have long been used as CER catalysts, they suffer from a selectivity problem due to the competing oxygen evolution reaction. To overcome this shortcoming, we have developed a new CER catalyst composed of atomically dispersed Pt–N 4 sites on carbon nanotubes (Pt 1 /CNT). In this study, we demonstrate that the catalytically active Pt–N 4 sites can be constructed from H 2 PtCl 6 ·6H 2 O and an ionic liquid via a bottom-up approach and a Pt-porphyrin-driven top-down method. Both catalysts exhibit excellent CER activity and remarkable selectivity, demonstrating the general efficacy of Pt 1 /CNT for the CER. The electrochemical and in situ X-ray absorption spectrosco…