Comparative CO2 Electroreduction by Cu7 Nanoclusters across Molecular, 1D, and 2D Reticular Architectures

Abstract Reticular chemistry is typically invoked to organize molecular building blocks, yet its ability to reprogram the intrinsic reactivity of atomically precise metal clusters remains largely unexplored. Here, we demonstrate dimensional reticulation as a decisive lever for tuning CO2 electroreduction by systematically comparing a thiolate-protected Cu7 nanocluster across molecular, one-dimensional (1D), and two-dimensional (2D) architectures. Coordination-driven assembly with linear and trigonal pyridyl linkers yields Cu7 MOF-1D and Cu7 MOF-2D, respectively, preserving cluster nuclearity while progressively transforming its geometric, electronic, and porous environment. Single-crystal analysis reveals that reticulation lifts the intrinsic metric degeneracy of the Cu7 core, imprinting directional distortions that intensify from 1D chains to 2D sheets. This evolution coincides with a transition from packing-limited solids to genuine microporous frameworks, culminating in a high-surface-area 2D material (659 m2 g–1) with enhanced CO2 uptake. These structural changes translate directly into electrocatalytic performance, where formate selectivity increases from 23.4% (Cu7 NC) to 39.0% (Cu7 MOF-2D), accompanied by a decreased Faradaic contribution of H2 despite increased overall cathodic activity. Post-reaction analyses show that the reticular frameworks retain their overall structural organization and predominantly low-valent, cluster-derived Cu coordination environments. Density functional theory reveals that reticulation strengthens CO2 binding, stabilizes *HCOO intermediates, and enriches electronic states near the Fermi level, collectively steering the reaction toward HCOOH formation. This work establishes reticular assembly as a multi-parameter strategy for programming cluster reactivity, transforming a single Cu7 motif into a hierarchy of catalytic states.