Nitrogen configuration engineering in carbon‐encapsulated Ni nanocatalysts for efficient <scp> CO ₂ </scp> / <scp> MgCO ₃ </scp> electroreduction

Abstract Electrocatalytic CO 2 reduction into value‐added products enables carbon cycling and renewable energy storage. Developing non‐precious metal catalysts with high activity, selectivity, and long‐term stability remains challenging. Herein, we design nitrogen‐doped carbon‐encapsulated Ni nanoparticles (Ni‐N‐C) using layered double hydroxide as precursors. The pyridinic‐to‐pyrrolic N ratio (Npy/Npr) is tuned by pyrolysis temperature. The optimal Ni‐N‐C‐750 (Npy/Npr ≈1) delivers a CO Faradaic efficiency of 97.8% at −1.5 V versus Ag/AgCl, maintains &gt;80% CO selectivity across a broad current density range, and exhibits &gt;100 h stability. The balanced N configuration optimizes the electronic structure, lowering the *COOH formation barrier while suppressing hydrogen evolution. Furthermore, using MgCO 3 as a solid carbon source enables tunable syngas (CO/H 2 up to ~0.1) and Mg(OH) 2 byproduct, demonstrating the coupling of carbonate conversion with CO 2 RR. This work establishes nitrogen configuration engineering as a design principle for efficient and durable carbon‐encapsulated electrocatalysts, providing a platform for coupling carbonate conversion.