Ionization of Porous Hypercrosslinked Polymers for Catalyzing Room-Temperature CO₂ Reduction via Formamides Synthesis

Abstract

Porous materials with heterogeneous nature occupy a pivotal position in the chemical industry. This work described a facile pre- and post-synthetic approach to modify porous hypercrosslinked polymer with quaternary ammonium bromide, rendering it as efficient catalyst for CO₂ conversion. The as-prepared porous ionic polymer (PiP@QA) displayed an improved specific surface area of 301 m²·g⁻¹ with hierarchically porous structure, good selective adsorption of CO₂, as well as high ion density. Accordingly, PiP@QA catalyst exhibited excellent catalytic performances for the solvent-free synthesis of various formamides from CO₂, amines and phenylsilane under 35 °C and 0.5 MPa. We speculated that the superior catalytic efficiency and broad substrate scope of this catalyst could be resulted from the synergistic effect of flexible ionic sites with unique nanoporous channel that might increase the collision probability of reactants and active sites as well as enhance the diffusion of reactants and products during the reaction process. With the good reusability, PiP@QA was also available for the efficient conversion of simulated flue gas (15% CO₂ in N₂, v/v) into target formamides with quantitative selectivity at room temperature, which further highlighted its industrial application potential in chemical recycling the real-word CO₂ to valuable products.

Graphic Abstract