Programmed intralayer Co and interlayer Ni atoms in a covalent organic framework for synergistic CO2 photoreduction

Abstract

The atom programming of multiple active centers is a central goal in advanced catalysis, yet it remains a formidable challenge, particularly for complex transformations like CO₂ photoconversion that require orchestrated multi-electron/proton pathways. Herein, we report an orthogonal site-encoding strategy, driven by coordination adaptability, that enables unprecedented atomic-level spatial programming within a dual-metal covalent organic framework (TZCOF), featuring precisely positioned intralayer CoNOCl₂ and interlayer NiN₂Cl₂ sites. This architecturally programmed CoNi-TZCOF exhibits exceptional performance, with a CO generation rate of 13.6 mmol g⁻¹ h⁻¹ (98.7% selectivity), significantly outperforming pristine TZCOF (51.6% selectivity), Co-TZCOF (88.5% selectivity), and Ni-TZCOF (85.9% selectivity) by factors of 41.2, 1.3, and 6.2, respectively. Moreover, in simulated flue gas containing 15% CO₂, CoNi-TZCOF also displays excellent CO production activity (12.9 mmol g⁻¹ h⁻¹, 96.5% selectivity), demonstrating its potential for industrial applications. Mechanistic investigations reveal a synergistic donor–acceptor interaction wherein the interlayer Ni sites modulate the electronic structure of the intralayer Co active centers, thereby optimizing the d-band center and facilitating the formation of the critical *COOH intermediate. This study establishes a powerful atom programming strategy for bimetallic sites within crystalline materials, paving the way toward designing catalysts with spatially controlled, multi-atomic architectures for complex chemical transformations.