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The utilization of catalysts comprising metal nanoparticle has been beneficial for enhancing the performance of oxygen reduction reaction (ORR). However, the inadequate intrinsic activity of these catalysts still presents a significant challenge, limiting their overall effectiveness. This issue can be addressed by introducing single atoms, which can create a synergistic effect with the nanoparticles to catalyse and thereby improve performance. Nevertheless, the synergistic catalysis of nanoparticles and single atoms is still under investigation. In this study, we fabricated a core‐shell structured carbon framework incorporating Fe single atoms and Bi nanoparticles through the pyrolysis of COF and MOF core‐shell structures. Introducing Fe single atoms into ZIF‐8, with Fe‐ZIF‐8 as the core and Bi‐containing COF as the shell, resulted in higher ORR activity. The catalyst exhibited a half‐wave potential of 0.867 V and a high current density of 6.68 mA cm−2 in 0.1 M KOH, which were comparable to those of Pt/C equivalent. This study provides new research concepts for exploring the application of single atoms and nanoparticles in catalytic oxygen reduction reactions through synergistic effects. [ABSTRACT FROM AUTHOR]

The catalytic performance for electrocatalytic CO2 reduction reaction (CO2RR) depends on the binding strength of the reactants and intermediates. Covalent organic frameworks (COFs) have been adopted to catalyze CO2RR, and their binding abilities are tuned via constructing donor‐acceptor (DA) systems. However, most DA COFs have single donor and acceptor units, which caused wide‐range but lacking accuracy in modulating the binding strength of intermediates. More elaborate regulation of the interactions with intermediates are necessary and challenge to construct high‐efficiency catalysts. Herein, the three‐component COF with D‐A‐A units was first constructed by introducing electron‐rich diarylamine unit, electron‐deficient benzothiazole and Co‐porphyrin units. Compared with two‐component COFs, the designed COF exhibit elevated electronic conductivity, enhanced reducibility, high efficiency charge transfer, further improving the electrocatalytic CO2RR performance with the faradic efficiency of 97.2 % at −0.8 V and high activity with the partial current density of 27.85 mA cm−2 at −1.0 V which exceed other two‐component COFs. Theoretical calculations demonstrate that catalytic sites in three‐component COF have suitable binding ability of the intermediates, which are benefit for formation of *COOH and desorption of *CO. This work offers valuable insights for the advancement of multi‐component COFs, enabling modulated charge transfer to improve the CO2RR activity. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) have been utilized for catalyzing the reduction of carbon dioxide (CO2RR) due to their atomic metal centers and controllable pore channels, which are facilitated by different covalent bonds. However, the exploration of boron‐based linkages in these catalytic COFs has been limited owing to potential instability. Herein, we present the construction of boronic ester‐linked COFs through nucleophilic substitution reactions in order to catalyze the CO2RR. The inclusion of abundant fluorine atoms within the frameworks enhances their hydrophobicity and subsequently improves water tolerance and chemical stability of COFs. The content of boron atoms in the COF linkages was carefully controlled, with COFs featuring a higher density of boron atoms exhibiting increased electronic conductivity, enhanced reductive ability, and stronger binding affinity towards CO2. Consequently, these COFs demonstrate improved activity and selectivity. The optimized COFs achieve the highest activity, achieving a turnover frequency of 1695.3 h−1 and a CO selectivity of 95.0 % at −0.9 V. Operando synchrotron radiation measurements confirm the stability of Co (II) atoms as catalytically active sites. By successfully constructing boronic ester‐linked COFs, we not only address potential instability concerns but also achieve exceptional catalytic performance for CO2RR. [ABSTRACT FROM AUTHOR]

To achieve high-efficiency catalysts for CO2 reduction reaction, various catalytic metal centres and linker molecules have been assembled into covalent organic frameworks. The amine-linkages enhance the binding ability of CO2 molecules, and the ionic frameworks enable to improve the electronic conductivity and the charge transfer along the frameworks. However, directly synthesis of covalent organic frameworks with amine-linkages and ionic frameworks is hardly achieved due to the electrostatic repulsion and predicament for the strength of the linkage. Herein, we demonstrate covalent organic frameworks for CO2 reduction reaction by modulating the linkers and linkages of the template covalent organic framework to build the correlation between the catalytic performance and the structures of covalent organic frameworks. Through the double modifications, the CO2 binding ability and the electronic states are well tuned, resulting in controllable activity and selectivity for CO2 reduction reaction. Notably, the dual-functional covalent organic framework achieves high selectivity with a maximum CO Faradaic efficiency of 97.32% and the turnover frequencies value of 9922.68 h−1, which are higher than those of the base covalent organic framework and the single-modified covalent organic frameworks. Moreover, the theoretical calculations further reveal that the higher activity is attributed to the easier formation of immediate *CO from COOH*. This study provides insights into developing covalent organic frameworks for CO2 reduction reaction. Covalent organic frameworks constructed with ionic skeletons and C-N linkages by multilevel post-synthetic modification. These frameworks achieved high activity and stability for electrocatalytic CO2 reduction. [ABSTRACT FROM AUTHOR]