Dual-atom-site catalysts (DACs) have emerged as an ew frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining the advantages of singleatom-site catalysts,such as almost 100 %atomic efficiency and excellent hydrocarbon selectivity.I nt his study,c obalt-based atom site catalysts with aC o 2 -N coordination structure were synthesized and used for photodriven CO 2 reduction. The resulting CoDAC containing 3.5 %C oa toms demonstrated asuperior atom ratio for CO 2 reduction catalytic performance, with 65.0 %C H 4 selectivity,w hichf ar exceeds that of cobaltbased single-atom-site catalysts (CoSACs). The intrinsic reason for the superior activity of CoDACsisthe excellent adsorption strength of CO 2 and CO* intermediates at dimeric Co active sites.

Dual‐atom‐site catalysts (DACs) have emerged as a new frontier in heterogeneous catalysis because the synergistic effect between adjacent metal atoms can promote their catalytic activity while maintaining the advantages of single‐atom‐site catalysts, such as almost 100 % atomic efficiency and excellent hydrocarbon selectivity. In this study, cobalt‐based atom site catalysts with a Co2–N coordination structure were synthesized and used for photodriven CO2 reduction. The resulting CoDAC containing 3.5 % Co atoms demonstrated a superior atom ratio for CO2 reduction catalytic performance, with 65.0 % CH4 selectivity, which far exceeds that of cobalt‐based single‐atom‐site catalysts (CoSACs). The intrinsic reason for the superior activity of CoDACs is the excellent adsorption strength of CO2 and CO* intermediates at dimeric Co active sites.

Constructing stable heterostructures with appropriate active site architectures in covalent organic frameworks (COFs) can improve the active site accessibility and facilitate charge transfer, thereby increasing the catalytic efficiency. Herein, a pore‐wall modification strategy is proposed to achieve regularly arranged TiO2 nanodots (≈1.82 nm) in the pores of COFs via site‐specific nucleation. The site‐specific nucleation strategy stabilizes the TiO2 nanodots as well as enables the controlled growth of TiO2 throughout the COFs’ matrix. In a typical process, the pore wall is modified and site‐specific nucleation is induced between the metal precursors and the organic walls of the COFs through a careful ligand selection, and the strongly bonded metal precursors drive the confined growth of ultrasmall TiO2 nanodots during the subsequent hydrolysis. This will result in remarkably improved surface reactions, owing to the superior catalytic activity of TiO2 nanodots functionalized to COFs through strong NTiO bonds. Furthermore, density functional theory studies reveal that pore‐wall modification is beneficial for inducing strong interactions between the COF and TiO2 and results in a large energy transfer via the NTiO bonds. This work highlights the feasibility of developing stable COF and metal oxide based heterostructures via organic wall modifications to produce carbon fuels by artificial photosynthesis.