Rational encapsulation of atomically precise nanoclusters into metal–organic frameworks by electrostatic attraction for CO2 conversion

Abstract

Controlled encapsulation of atomically precise nanoclusters (APNCs) into metal–organic frameworks (MOFs) has been an efficient way to create new types of multifunctional crystalline porous materials. Such hybrids (APNCs@MOFs) provide ideal candidates for studying inherent structure–catalysis relationships owing to the well-defined compositions of both components. Moreover, modeling of APNCs@MOFs with precise structures would be more reliable. Herein, we have established an “Electrostatic Attraction Strategy” to synthesize APNCs@MOF catalysts and studied their performance as catalysts for the conversion of CO₂. The synthetic strategy presented here has been proved to be general, as evidenced by the syntheses of various APNCs@MOF catalysts including all the combinations of [Au₁₂Ag₃₂(SR)₃₀]⁴⁻, [Ag₄₄(SR)₃₀]⁴⁻, and [Ag₁₂Cu₂₈(SR)₃₀]⁴⁻ nanoclusters with ZIF-8, ZIF-67, and MHCF frameworks. In particular, the as-obtained Au₁₂Ag₃₂(SR)₃₀@ZIF-8 composite shows excellent performance in capturing CO₂ and converting phenylacetylene into phenylpropiolate under mild conditions (50 °C and ambient CO₂ pressure) with a TON as high as 18 164, far exceeding those of most known catalysts. What's more, the catalyst is very stable and reused 5 times without loss of catalytic activity. We anticipate that this general synthetic approach may open up a new frontier in the development of promising APNCs@MOF catalysts, which can be applied in a broad range of heterogeneous catalyses in the future.