Mixed matrix membranes (MMMs) are a promising alternative to conventional polymeric membranes but suffer from compatibility issues of polymer and filler. This study reports simultaneous improvement in CO2 permeability and selectivity employing novel metal organic frameworks (MOFs), namely NOTT-300 and Pebax®1657 as polymer matrix. MMMs are characterized and investigated for separation of CO2/CH4 and CO2/N2 gas mixtures at ambient and elevated temperatures. Well-dispersed NOTT-300 particles are observed in SEM images of MMMs with no visible defects even at higher loadings. Single and mixed gas permeation results showed their outstanding performance exhibiting a simultaneous upsurge in CO2 permeability and CO2/CH4 and CO2/N2 selectivity. In comparison to neat Pebax®1657 membrane, the incorporation of NOTT-300 at 40% filler loading enhanced the permeability of CO2 by 380%, and selectivity to 68% and 26% for CO2/CH4 and CO2/N2 respectively. The results proved the potential of NOTT-300 as filler material for MMMs aimed at CO2 capture because of their high porosity and CO2 philic properties.