Novel HBD-Containing Zn (dobdc) (datz) as efficiently heterogeneous catalyst for CO2 chemical conversion under mild conditions

Abstract

A novel Zn-based metal–organic framework Zn (dobdc) (datz) [Zn2(H2dobdc) (datz)2·1.5DMF] with plentiful hydrogen bond donors (HBD) groups was facilely synthesized from mixed ligands. The dual activation of metal Zn sites and HBD groups for epoxides by forming Zn–O adduct and hydrogen bonds facilitated the ring-opening of epoxide substrate, which is critical for the subsequent CO2 fixation. Also, the existence of micropores and N-rich units in Zn (dobdc) (datz) afforded affinity towards CO2, which is beneficial to further improvement on catalytic CO2 conversion performance. Satisfactorily, Zn (dobdc) (datz)/Bu4NBr system was proved efficient heterogeneous catalyst for the CO2 cycloaddition with epoxides, and 98% propylene carbonate yield was obtained under mild conditions (80 °C, 1.5 MPa and solvent-free). In addition, Zn (dobdc) (datz)/Bu4NBr exhibited remarkable versatility to different epoxides and could be completely recycled over six runs with high catalytic activity. The highly stable, easily recycle and solvent-free Zn-based MOF reported here displays eco-friendly and efficient performance to CO2 conversion.