One-Pot Synthesis of Triazine-Embedded Hierarchically Porous Organosilica Polymers via Tandem Condensation for Carbon Capture and Conversion

Abstract

A simple one-step route for designing three covalently bonded porous organosilica polymers via tandem condensation, bearing an adjustable triazine moiety and N–Si cooperative microenvironments, has been reported for the first time. In contrast to the traditional methods that rely on prefabricated supports or postsynthetic triazine integration, our strategy allows triazine moieties to be covalently embedded in situ inside the silica backbone, providing uniform distribution and improved structural integrity. The produced silica-based porous organic polymers (POPs) have high thermal stability (up to 250 °C) along with high specific surface areas (200–600 m2g–1). The presence of hierarchical porosity (meso- and microporosity) guarantees quick diffusion of the reactant and intermediates during catalytic reactions in addition to facilitating efficient CO2 adsorption at the pore surfaces. Using this structural advantage, a two-step CO2-valorization method was investigated: first, CO2 was converted to cyclic carbonates, and then it was reduced to methanol. Due to high porosity and easily accessible active sites, these hybrid materials catalyze the transformation of the carbonate to methanol, facilitating effective hydride transfer and intermediate conversion. Among the three silica-incorporated POPs, SL-1-Silica-POP produced the highest methanol yield of 20.5 mmol g–1 in the hydrogenation of epichlorohydrin carbonate by using phenylsilane as the hydride source.