Rational self-assembly of triazine- and urea-functionalized periodic mesoporous organosilicas for efficient CO2 adsorption and conversion into cyclic carbonates

The development of advanced multifunctional nanomaterials for selective CO2 conversion remains a major challenge. Herein, novel triazine- and urea-functionalized periodic mesoporous organosilicas (TUF-PMOs) were constructed and structurally characterized by a facile hydrothermal self-assembly method. The obtained TUF-PMOs integrate multiple hydrogen bond donor and Lewis base sites, and have high surface area and well-ordered mesoporous channel. They were used for CO2 adsorption and catalyzing CO2/epoxide cycloaddition reaction. The effects of active group contents, various cocatalysts and reaction conditions on the cycloaddition reaction were examined. The optimum TUF-PMO-20 displays good bifunctionality for CO2 adsorption and conversion when combining with tetrabutylammonium iodide (TBAI) cocatalyst under mild and green conditions. Moreover, the TUF-PMO-20 catalyst shows exciting reusability and versatility. Finally a cooperating catalytic mechanism of TUF-PMO/TBAI system in CO2 cycloaddition reaction was provided. The present work provides a new avenue for the application of task-specific hybrid organosilicon materials in CO2 activation and conversion.