Coordinatively Unsaturated Metal–Nitrogen Active Sites at Twisted Surfaces in Metallic Porous Nitride Single Crystals Delivering Enhanced Electrocatalysis Activity

Abstract

To create active sites on surfaces, the identification of structural features that could confine the local‐defect structure in the lattice is required. Porous nitride single crystals, combining the advantages of porosity and structural coherence, provide the possibility to create coordinatively unsaturated metal–nitrogen active sites confined on surfaces. For the first time, ordered active sites and tailor the atomically resolved Fe−N and Co−N local structures are created through control of the unsaturated nitrogen coordination at twisted surfaces in porous single‐crystalline FenN (n=2–4) and ConN (n=1–3) nanocubes. The precise tailoring of the electronic structures of these coordinatively unsaturated active sites therefore engineer the catalytic activity. Optimum electrocatalysis performances are observed with the porous Fe4N and Co3N nanocubes with highly unsaturated nitrogen coordination for selective nitrate reduction to ammonia and nitrobenzene amination to aminobenzene, while the structural coherence of these porous nitride single crystals delivers excellent durability.

Enhanced CO oxidation with cobalt-impregnated porous single-crystal manganese oxides

“…30,31 Porous single crystals have the advantages of both long-range ordered lattice structure and disordered connected pore structure, which can provide structural coherence and long-distance electronic connectivity, thus reducing the energy loss at grain boundaries and maintaining high stability and activity. 32 Porous single crystals have a clear lattice structure, precise chemical composition and clear termination surface, which can construct a continuous highly distorted active surface and fine structure, which is of great significance for studying the surface structure and reversible chemical mechanism of the electrochemical process. Therefore, the study of porous single crystals as catalytic base material is very important.…”