Advanced Design of Metal Nanoclusters and Single Atoms Embedded in C1N1‐Derived Carbon Materials for ORR, HER, and OER

Abstract Single atoms and nanoclusters of Fe, Ni, Co, Cu, and Mn are systematically designed and embedded in a well‐defined C 1 N 1 ‐type material that has internal cavities of ≈0.6 nm based on four N atoms. These N atoms serve as perfect anchoring points for the nucleation of small nanoclusters of different metal natures through the creation of metal‐nitrogen (TM‐N 4 ) bonds. After pyrolysis at 800 °C, TM@CN x ‐type structures are obtained, where TM is the transition metal and x < 1. Fe@CN x and Co@CN x are the most promising for oxygen reduction reaction and hydrogen evolution reaction, respectively, with a Pt‐like performance, and Ni@CN x is the most active for oxygen evolution reaction (OER) with an E OER of 1.59 V versus RHE, far outperforming the commercial IrO 2 ( E OER = 1.72 V). This systematic and benchmarking study can serve as a basis for the future design of advanced multi‐functional electrocatalysts by modulating and combining the metallic nature of nanoclusters and single atoms.