Programmatically Installing Metal in One‐Dimensional Covalent Organic Framework for Electrocatalytic Reduction of CO ₂

Comprehensive Summary Metalated covalent organic frameworks (COFs) with two‐ or three‐dimensional (2D/3D) topologies have been extensively studied for various applications. In contrast, their one‐dimensional (1D) analogues remain largely unexplored, especially for the electrocatalytic CO 2 reduction reaction (CO 2 RR). Herein, we report the design and synthesis of a novel 1D metalated COF, denoted as Por‐PBA, constructed via the condensation of 4,4’‐(1,10‐phenanthroline‐2,9‐diyl)dibenzaldehyde (PBA) and 5,10,15,20‐tetrakis(4‐aminophenyl)porphyrin (Por). Upon incorporation of Co ions into Por units, the monometallic CoPor‐PBA exhibits enhanced electrocatalytic CO 2 RR performance compared to Por‐PBA. Interestingly, by programmatical installation of the secondary Fe ions into the PBA moieties, the optimized bimetallic CoPor‐Fe 0.22 PBA shows significantly enhanced CO 2 RR performance relative to the monometallic CoPor‐PBA. Particularly, CoPor‐Fe 0.22 PBA achieves a Faradaic efficiency for CO (FE CO ) of 100% at both –0.7 and –0.8 V vs. reversible hydrogen electrode (RHE), with corresponding partial CO current densities of −3.7 and −6.4 mA·cm −2 , respectively. Mechanistic studies further confirmed the formation of key *COOH and *CO intermediates during the CO 2 RR process on CoPor‐Fe 0.22 PBA. This work highlights the promise of 1D metalated COFs as efficient platforms for CO 2 conversion and underscores the importance of metal‐site engineering in developing high‐performance COF‐based catalysts.