Polymer-derived organoamine-functionalized amorphous silica materials for CO₂ capture

抄録

Amorphous silica-based alkylamine-functionalized hybrid membrane materials were synthesized through polymer-derived ceramics (PDCs) route, in order to selectively transport CO₂. Commercially available perhydropolysilazane (PHPS) was chemically modified with primary and secondary amino silane derivatives, and subsequently oxidized in air at room temperature to afford alkylamine-functionalized amorphous silica materials. CO₂ uptake by the powdered samples was investigated by the thermogravimetric analysis under CO₂ atmosphere, in-situ diffuse reflectance infrared fourier transform spectroscopic analysis and measurement of CO₂ sorption isotherm. In the case of alkylamine-functionalized silica samples, CO₂ uptake mechanism involved chemisorption at very low partial pressures and physisorption at higher partial pressures, demonstrated by the temperature dependence of CO₂ isotherms. The reaction paths and sorption mechanisms related to the nature of the functionalized amino groups were discussed from a viewpoint to develop CO₂-selective facilitated transport ceramic-based membranes.