Abstract Carbon capture from different CO 2 ‐enriched sources demands the establishment of cleaner innovations to make strides in improving the existing worldwide environment. Nanoparticles of inorganic copper‐based metal–organic framework (Cu‐MOF) have been impregnated in varying loadings into an intrinsically microporous polymer (PIM‐1) to concoct mixed‐matrix membranes (MMMs) for carbon capture applications. The impacts of Cu‐MOF doping and temperatures of feed gas streams on morphology and carbon detainment capability of manufactured membranes were investigated. The carbon seizing capacity of different membranes was assessed by estimating permeabilities, selectivities, dissemination and dissolvability coefficients, facilitation proportions, and activation energies. Compared with the unfilled PIM‐1 membrane, impregnation of 30% Cu‐MOF into polymer significantly enhanced CO 2 penetrability from 3740 to 6360 Barrer together with CO 2 /N 2 and CO 2 /CH 4 selectivity advancements from 27 to 34 and from 16 to 18, respectively. Performing gas penetration tests at elevated temperatures raised the CO 2 penetrability of the membrane. The carbon seizing capability of MMMs lying over Robeson's bound signifies their potential in various cleansing operations.