Integration of CO2 capture, activation, and conversion with a ternary acetylglucosyl 2-methyl-imidazolium modified Pd catalyst

Abstract

The efficient catalytic conversion of thermodynamically and kinetically stable carbon dioxide (CO₂) into value-added chemicals is challenging. Herein, we developed a high-efficiency ternary Pd catalyst (AcGlu-MeIm-PdCl₄) modified with acetylglucosyl 2-methyl-imidazolium for the integration of CO₂ capture, activation, and catalytic conversion simultaneously. The Lewis acid–Lewis base interactions between CO₂ and AcGlu groups increased the solubility of CO₂, while the N-heterocyclic olefin (NHO) derived from 2-methyl-imidazolium cations can capture and activate CO₂ by forming NHO-CO₂ adducts, as well as stabilizing the metal Pd. 2-Oxazolidinones can be prepared even using dilute CO₂ (CO₂/N₂, vol/vol = 15 : 85) and propargyl amines over this ternary Pd catalyst, achieving a record turnover frequency of 1440 h⁻¹. The CO₂ capture, activation, and conversion mechanism of this catalytic system was unveiled by quasi-in situ NMR, ¹³C-isotope-labeling NMR and FT-IR. These findings highlight the potential of exploring multifunctional catalysts for efficient catalytic CO₂ conversion.