The electrocatalytic CO₂ reduction reaction (eCO₂RR) stands out as a highly promising approach to simultaneously resolving the issue of the elevated atmospheric CO₂ concentration and its utilization to produce value-added products. One of the present challenges is the rational design of efficient catalysts toward the eCO₂RR and the understanding of their structure–activity relationship. Covalent porous catalysts (CPCs) with atomically dispersed active sites embedded in the porous organic backbone, including polymer-based catalysts, such as covalent organic frameworks (COFs) and conjugated microporous polymers (CMPs), and molecule-based catalysts, such as porous organic cages (POCs) have received increasing attention recently. They feature extremely high atom utilization, customizable porosity, a customizable backbone, and distinct electronic properties. In this review, the design principles of CPCs, both in their selection of metal sites (metallic centers, heterometallic centers and their axial coordination) and optimization of organic backbones (chelating sites, their electronic modulation and microstructures) will be covered, aiming to provide guidance to tune their eCO₂RR performance. Then representative examples will be discussed to reveal their structure–activity relationships. The perspective and key challenges in CPC based eCO₂RR electrocatalysts will be finally proposed.

中文翻译：

---

用于电化学还原 CO2 的共价多孔催化剂

电催化CO ₂还原反应(eCO _{2 RR) 是一种非常有前景的方法，可以同时解决大气CO 2}浓度升高的问题并利用其生产增值产品。目前的挑战之一是针对 eCO ₂ RR 的高效催化剂的合理设计以及对其结构-活性关系的理解。具有嵌入多孔有机骨架中的原子分散活性位点的共价多孔催化剂（CPC），包括基于聚合物的催化剂，例如共价有机骨架（COF）和共轭微孔聚合物（CMP），以及基于分子的催化剂，例如多孔有机催化剂笼子（POC）最近受到越来越多的关注。它们具有极高的原子利用率、可定制的孔隙率、可定制的主链和独特的电子特性。在这篇综述中，将涵盖CPC的设计原则，包括金属位点（金属中心、异金属中心及其轴向配位）的选择和有机主链的优化（螯合位点、其电子调制和微结构），旨在提供调整其 eCO ₂ RR 性能的指导。然后将讨论代表性例子以揭示它们的结构-活性关系。最后将提出基于CPC的eCO ₂ RR电催化剂的前景和主要挑战。