Binary Atomically Dispersed Metal‐Site Catalysts with Core−Shell Nanostructures for O₂ and CO₂ Reduction Reactions

Abstract

Engineering atomically dispersed metal site catalysts with controlled local coordination environments and 3D nanostructures effectively improves the catalytic performance for the oxygen reduction reaction (ORR) and the carbon dioxide reduction reaction (CO2RR), which are critical for clean energy conversion and chemical production. Herein, an innovative approach for preparing core−shell nanostructured catalysts with different single‐metal sites in the core and the shell, respectively, is developed. In particular, as the shell precursors, covalent organic polymers with a thin layered structure that is polymerized in situ and coated on a metal‐doped ZIF‐derived carbon core are used, followed by a controlled thermal activation. The selective combination and construction of different metal sites increase active site density in the surface layers, promote structural robustness, facilitate mass/charge transfer, and yield a possible synergy of active sites in the core and the shell. The p‐FeNC(shell)@CoNC(core), consisting of a polymerized FeTPPCl‐derived carbon layer (p‐FeNC) on a Co‐doped ZIF‐derived carbon (CoNC), exhibits remarkable ORR activity and stability in acidic media along with encouraging durability in H2–air fuel cells. Likewise, a p‐FeNC(shell)@NiNC(core) catalyst demonstrates outstanding CO2RR activity and stability. Hence, integrating two appropriate single‐metal sites in core and shell precursors, respectively, can modulate morphological and catalytic properties for a possible synergy toward different electrocatalysis processes.

Atomically Dispersed Fe-Co Bimetallic Catalysts for the Promoted Electroreduction of Carbon Dioxide

“…1.6 Å, which can be ascribed to the Co–N, Co–O, and Co–C coordination, indicating the single-atom state of Co atoms. Several previous studies confirm that metal-N bonds dominate similarly as the peak in ZIF-8 derived SACs [ 8 , 33 , 35 ]. Combined with the XPS results, this peak could be plausibly assigned to Co–N bindings.…”

Tuning Two‐Electron Oxygen‐Reduction Pathways for H2O2 Electrosynthesis via Engineering Atomically Dispersed Single Metal Site Catalysts

“…Generally, the metal center in M-N-C catalysts is coordinated with four nitrogen atoms. [160][161][162][163][164] However, this coordination structure does not always possess the optimized binding energy for oxygenated intermediates and the best catalytic performance. As a vital parameter and descriptor to rationalize the relationship between structure and performance, the coordination number can be changed by varying thermal activation temperatures, [165][166][167] which modifies the electronic configuration and coordination structure of metal centers.…”

Research Progress and Application of Single-Atom Catalysts: A Review

“…The single-atom catalyst electrocatalytic CO 2 reduction reaction can convert greenhouse gases into high value-added chemicals or fuels, which can achieve sustainable goals [88,89]. Atomically dispersed mono-atomic catalysts are one of the most attractive electrocatalysts for the CO 2 reduction reaction (ORR) [90]. As a new electrode material, a mono-atomic catalyst can cope with the challenges of slow dynamics of CO 2 RR and low Faraday efficiency.…”