Abstract:
The concentration of carbon dioxide (CO2) in the
atmosphere is increasing at an alarming rate resulting in
undesirable environmental issues. To mitigate this growing
concentration of CO2, selective carbon capture and storage/
sequestration (CCS) are being investigated intensively. However, CCS technology is considered as an expensive and
energy-intensive process. In this context, selective carbon
capture and utilization (CCU) as a C1 feedstock to synthesize
value-added chemicals and fuels is a promising step towards
lowering the concentration of the atmospheric CO2 and for
the production of high-value chemicals. Towards this direction, several strategies have been developed to convert CO2,
a Greenhouse gas (GHG) into useful chemicals by forming
C N, C O, C C, and C H bonds. Among the various CO2
functionalization processes known, the cycloaddition of CO2
to epoxides has gained considerable interest owing to its
100% atom-economic nature producing cyclic carbonates or
polycarbonates in high yield and selectivity. Among the
various classes of catalysts studied for cycloaddition of CO2 to
cyclic carbonates, porous metal-organic frameworks (MOFs)
have gained a special interest due to their modular nature
facilitating the introduction of a high density of Lewis acidic
(LA) and CO2-philic Lewis basic (LB) functionalities. However,
most of the MOF-based catalysts reported for cycloaddition
of CO2 to respective cyclic carbonates in high yields require
additional co-catalyst, say tetra-n-butylammonium bromide
(TBAB). On the contrary, the co-catalyst-free conversion of
CO2 using rationally designed MOFs composed of both LA
and LB sites is relatively less studied. In this review, we
provide a comprehensive account of the research progress in
the design of MOF based catalysts for environment-friendly,
co-catalyst-free fixation of CO2 into cyclic carbonat
