Construction of a dual-cage-based MOF with uncoordinated nitrogen sites for CO2 adsorption and fixation

A new dual-cage-based porous metal-organic framework (MOF, termed DZU-113) assembly from the triazolecarboxylate linker and the Cu(II) paddle-wheel unit was solvothermally constructed. The structure of DZU-113 was determined by single-crystal X-ray diffraction, being consisted of the octahedral cage with an internal diameter of approximately 0.4 nm, and the spindle nano-cage with internal pores of about 0.8 nm x 2.2 nm, respectively. Specially, the uncoordinated N atoms of triazole groups are distributed in the bottleneck windows of the spindle nano-cage, serving as open functional sites. DZU-113 has permanent porosity with the Brunauer-Emmett-Teller surface area of 1207 m2 g-1. The CO2 adsorption test demonstrated that the total uptake of DZU-113 can reach 66.7 cm3 g-1 at 298 K, and 112.0 cm3 g-1 at 273 K, 1 bar. Moreover, it achieves robust catalytic performance for the cycloaddition of CO2 and epoxides under mild conditions.

Automated summary

A new dual-cage-based porous metal-organic framework (MOF) DZU-113 with highly controllable pore structure and excellent CO2 adsorption performance was successfully constructed. The study is of great significance for improving the efficiency of CO2 capture and catalytic conversion.