Exceptionally Robust In-Based Metal–Organic Framework for Highly Efficient Carbon Dioxide Capture and Conversion

An
In-based metal–organic framework, with 1D nanotubular open
channels, In2(OH)­(btc)­(Hbtc)0.4(L)0.6·3H2O (1), has been synthesized via
an in situ ligand reaction, in which 1,2,4-H3btc is partially
transformed into the L ligand. Compound 1 exhibits exceptional
thermal and chemical stability, especially in water or acidic media.
The activated 1 presents highly selective sorption of
carbon dioxide (CO2) over dinitrogen. Interestingly, diffuse-reflectance
infrared Fourier transform spectroscopy with a carbon monoxide probe
molecule demonstrates that both Lewis and Brønsted acid sites
are involved in compound 1. As a result, as a heterogeneous
Lewis and Brønsted acid bifunctional catalyst, 1 possesses excellent activity and recyclability for chemical fixation
of CO2 coupling with epoxides into cyclic carbonates under
mild conditions. In addition, the mechanism for the CO2 cycloaddition reaction has also been discussed.