This review comprehensively summarizes the progress on the structural and electronic modulation of transition metal nitrides for electrochemical energy applications.

Developing efficient and stable non‐noble electrocatalysts for the oxygen evolution reaction (OER) remains challenging for practical applications. While nickel–iron layered double hydroxides (NiFe‐LDH) are emerging as prominent candidates with promising OER activity, their catalytic performance is still restricted by the limited active sites, poor conductivity and durability. Herein, hierarchical nickel–iron–cobalt LDH nanosheets/carbon fibers (NiFeCo‐LDH/CF) are synthesized through solvent‐thermal treatment of ZIF‐67/CF. Extended X‐ray adsorption fine structure analyses reveal that the Co substitution can stabilize the Fe local coordination environment and facilitate the π‐symmetry bonding orbital in NiFeCo‐LDH/CF, thus modifying the electronic structures. Coupling with the structural advantages, including the largely exposed active surface sites and facilitated charge transfer pathway ensured by CF, the resultant NiFeCo‐LDH/CF exhibits excellent OER activity with an overpotential of 249 mV at 10 mA cm−1 as well as robust stability over 20 h.

Encapsulation of metal nanocatalysts by supportderived materials is well known as a classical strong metal−support interaction (SMSI) effect that occurs almost exclusively with active oxide supports and often blocks metal-catalyzed surface reactions. In the present work this classical SMSI process has been surprisingly observed between metal nanoparticles, e.g., Ni, Fe, Co, and Ru, and inert hexagonal boron nitride (h-BN) nanosheets. We find that weak oxidizing gases such as CO 2 and H 2 O induce the encapsulation of nickel (Ni) nanoparticles by ultrathin boron oxide (BO x ) overlayers derived from the h-BN support (Ni@BO x / h-BN) during the dry reforming of methane (DRM) reaction. Insitu surface characterization and theory calculations reveal that surface B−O and B−OH sites in the formed BO x encapsulation overlayers work synergistically with surface Ni sites to promote the DRM process rather than blocking the surface reactions.

The confinement effect of h-BN shells helps to maintain active metallic Ni cores and strengthen the HOR processes occurring at h-BN/Ni interfaces.