Construction of stable MOFs integrated with open metal sites and amine groups for CO2 capture and conversion

CO2 is deemed as the major greenhouse gas causing global warming over the past several decades. Developing porous solid materials to achieve the capture and utilization of CO2, in this work, two metal–organic frameworks, [Ni2(5H-Ade)(TCPE)(H2O)3]·3DMF·6H2O (Ni-Ade-TCPE), and [Co4.5(HCOO)3(4H-Ade)2(TCPE)(H2O)5]·5DMF·7H2O (Co-Ade-TCPE) have been synthesized by employing mixed adenine and tetrakis(4-carboxyphenyl)ethylene (H4TCPE). The structural analysis demonstrates they are 3D frameworks possessing 1D open channels with –NH2 groups and open metal sites modified surfaces. They display impressive chemical stability in acidic and basic water solutions and high adsorption capacity for CO2. At 70 ​°C and 1 ​bar, Ni-Ade-TCPE exhibits outstanding activity, selectivity, and recyclability in the cycloaddition reaction of epoxides with CO2 due to Lewis acid–base bifunctional sites. Moreover, a reasonable catalytic reaction mechanism has been proposed.