Staggered ABC‐Stacking Cobalt‐Triptycene Framework for Accelerating CO ₂ Photoreduction

Abstract

Abstract Metal‐organic frameworks (MOFs) are highly efficient photocatalysts due to their highly tunable structures and favorable electronic properties. However, achieving control over framework stacking arrangements, such as the staggered ABC‐stacking, presents significant challenges. This difficulty arises from the inherently unfavorable energetics of the ABC arrangement and weaker π–π interactions compared to other stacking modes. Herein, a cobalt‐triptycene framework with a staggered ABC‐stacking arrangement was successfully synthesized in the aqueous phase, achieving a 90% yield. Experimental evaluations revealed that this framework achieved a CO production rate of 4.43 mmol g −1  h −1 , which is comparable to the most reported MOF‐based photocatalysts for CO 2 reduction. Moreover, density functional theory (DFT) calculations and molecular dynamics (MD) simulations indicated that the ABC‐stacking cobalt‐triptycene framework exhibits lower activation energy (0.079 eV) for water molecules, reduced Gibbs free energies for key intermediates *COOH (0.76 eV) and *H (0.73 eV), and the highest reaction rate increment (7.488 times). Furthermore, principal component analysis (PCA) reveals a strong correlation between the CO production rate and factors such as the Ik value, optical bandgap, and Δ G *H , revising the previous held notion that Δ G *COOH is the primary determinant of catalytic performance. These results offer valuable insights into the design principles of advanced photocatalysts for CO 2 reduction.