Boosted mass transfer and water tolerance in CO2 cycloaddition via hierarchically porous PVMDMS@PVP aerogel containing in-situ grown UiO-66-NH2

초록

A covalently co-networked poly(vinylmethyldimethoxysilane) polyvinylpyrrolidone (PVMDMS@PVP) aerogel scaffold enables in-situ growth of UiO-66-NH, and grafting of 1-methylacetamido-3-methylimidazolium bromide ([MAmim]Br), forming a monolithic catalyst for integrated carbon dioxide (CO2) capture and cycloaddition reaction. Tuning PVP content (5-20 wt%) during sol-gel synthesis yields a hierarchically porous network (>1,000 mg) that resists collapse under solvothermal conditions. Solvothermal crystallization within the network produces uniformly dispersed UiO-66-NH2 (similar to 34 wt%) without pore blockage, and ionic liqud (IL) grafting introduces dual sites for CO2 adsorption and epoxide activation. The composite achieves 2.8 mmol g(1) CO2 uptake at 25 degrees C and promotes solvent- and co-catalyst-free cycloaddition of allyl glycidyl ether (AGE) at 120 degrees C, 0.6 MPa CO2 to > 99% conversion and selectivity with 0.151 mol % catalyst loading. Ten consecutive adsorption-desorption and reaction cycles retain >97% of activity and structural integrity. An apparent activation energy of 37.5 kJ mol (vs. 47.8 kJ mol for UiO-66-NH2-IL) highlights accelerated kinetics. Exceptional water tolerance and multi-cycle stability underscore its potential as a scalable platform for practical CO2 valorization.

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