  The global rate of anthropogenic CO2 emission is rising, which urges the
development of efficient carbon capture and storage (CCS) technologies. Among
the various CO2 capture methods, adsorption by the linkers of the Metal-Organic
Frameworks (MOFs) materials has received more interest as excellent CO2
adsorbents because of their important role in understanding the interaction
mechanism for CO2 adsorption. Here, we investigate the adsorption of CO2
molecules at the center and side positions of several MOF-linkers using
molecular cluster models. The interaction between CO2 and the linkers is
approximated by computing the binding enthalpy ({\Delta}H) through the first
principles-based Density Functional Theory with Grimmes dispersion correction
(i.e., B3LYP-D3) and second-order Moller Plesset Theory (MP2). The computed
values of {\Delta}H indicate the weak nature of CO2 adsorption on the pristine
linkers, hence the strategy of lithium decoration is used to see its impact on
the binding strength. Among the various linkers tested, CO2 adsorbing at the
side position of the DFBDC-2 linker has strong adsorption with {\Delta}H value
of about -35.32 kJ/mol computed by the B3LYP-D3 method. The Energy
Decomposition Analysis (EDA) study reveals that among all the energy terms, the
contribution of electrostatic and polarization energy terms to the {\Delta}H
value are the most dominant one. Furthermore, the results of Frontier Molecular
Orbital Analysis (FMO) revealed that all the linkers remained stable even after
Li-decoration. The results of our investigations will direct towards the
development and synthesis of novel adsorbents with enhanced CO2 adsorption.
