Porous metal-organic framework with Lewis acid−base bifunctional sites for high efficient CO2 adsorption and catalytic conversion to cyclic carbonates.

A highly porous three-dimensional (3D) metal−organic framework (MOF) [Ni 3 (BTC) 2 (MA)(H 2 O)](DMF) 7 (1) incorporating both exposed metal sites and nitrogen-rich melamine was successfully constructed via solvothermal assembly of 1,3,5-benzenetricarboxylic acid (H 3 BTC), melamine (MA) and Ni(II) ions. The resulting activated Ni(II)-MOF-1a features high CO 2 loading capacity and excellent CO 2 affinity due to the Lewis-base property together with abundant micropores. The heterogeneous catalytic activity of the activated Ni(II)-MOF-1a was confirmed by remarkably high efficiency on CO 2 cycloaddition with small epoxides under ambient conditions. Moreover, the Ni(II)-MOF-1a exhibited satisfied stability and versatility, and it was easy to recycle with no obvious decrease of catalytic activity. Then the feasible synergistic mechanism of Ni(II)-MOF/Bu 4 NBr catalysts for CO 2 conversion was proposed. A highly porous MOF incorporating both exposed metal sites and nitrogen-rich melamine was successfully constructed via solvothermal reaction. The obtained Ni(II)-MOF-1 features high CO 2 loading capacity and excellent CO 2 affinity due to the Lewis-base property together with abundant micropores. The heterogeneous catalytic activity of the activated Ni(II)-MOF-1 was confirmed by remarkably high efficiency on CO 2 cycloaddition with small epoxides under ambient conditions. Moreover, the Ni(II)-MOF-1 exhibited satisfied stability and versatility, and it was easy to recycle with no obvious decrease of catalytic activity. Then the feasible synergistic mechanism of Ni(II)-MOF/Bu 4 NBr catalysts for CO 2 conversion was proposed. Unlabelled Image • A new porous Ni(II)-organic framework with Lewis acid−base bifunctional sites has been synthesized. • It shows excellent CO 2 sorption capacity around room temperature. • It shows remarkably high efficiency on CO 2 cycloaddition with small epoxides under ambient conditions. [ABSTRACT FROM AUTHOR]