Atomic Pt‐N4 Sites in Porous N‐Doped Nanocarbons for Enhanced On‐Site Chlorination Coupled with H2 Evolution in Acidic Water

Abstract

AbstractAcidic water electrolysis (AWE) has the potential to revolutionize green H2 generation with flexible partial load range, high gas purity, and rapid system response. However, the extensive usage of noble Ru/Ir metals and sluggish oxygen evolution reaction (OER) with inexpensive O2 products pose significant challenges in anodes. Herein, it is demonstrated that ultralow Pt single atoms in highly porous N‐doped carbons (Pt1/p‐NC@CNTs) can effectively catalyze chlorine evolution reaction (CER) for on‐site chlorination to replace OER in AWE, with 200 mV potential saving at 10 mA cm−2. As a result, various organic halide motifs of pharmaceutical molecules by chlorinating anisole, ketones, and olefins can be realized, along with H2 coproduction. Combined physicochemical characterizations including synchrotron X‐ray absorption spectroscopy, finite element methodsimulations, and theory calculations indicate that atomic Pt‐N4 active sites balance the adsorption/desorption of Cl intermediates (Volmer step) and the plentiful porosity of Pt1/p‐NC@CNTs with high specific surface area of 313 m2 g−1 enriches Cl− around active sites (Heyrovský step), collectively promoting the rate‐limiting Volmer–Heyrovský pathway for improved CER.