Efficient hydrogen isotope separation is crucial for applications in energy production and advanced scientific research, but separation of these poses significant challenges. In this study, we developed amorphous microporous carbon (AMC) derived from a zeolite template and explored hydrogen isotope separation using quantum sieving. Thermal desorption spectroscopy (TDS) technique was used to evaluate the selectivity of hydrogen (H-2) and deuterium (D-2) isotope separation. The doping of metal ions, such as Ca-2*, Mg-2*, Ni-2*, and Cu-2*, in the porous carbon modulates the physicochemical properties of the pores. The metal-doped carbon samples demonstrated D-2 vs H-2 selectivity (S D-2/H-2 ) of over 10, compared to the pristine carbon's S D-2/H-2 of less than 8. Density functional theory (DFT) calculation infers that pore modulation through metal doping enhanced the binding affinity of materials towards D-2 resulting in increased separation selectivity compared to pristine carbon samples. This approach not only boosts separation efficiency but also provides a scalable and cost-effective solution for industrial applications.