In this study egg white was used as a source of natural amino acids to modify the surface properties of palm shell-based activated carbon to enhance its CO ₂ capture performance. A simple impregnation method was employed for this purpose. Characterisation analysis was performed on the egg white-impregnated activated carbon to examine any changes in its surface properties before the CO ₂ adsorption test. The modified adsorbent showed high thermal stability below 300 °C and comprised of a new amide functional group. Furthermore, the modified adsorbent exhibited a 31% higher breakthrough time and maintained its CO ₂ adsorption capacity at 0.3 mmol/g, in comparison to raw activated carbon, regardless of the surface area and micropore volume reductions of 17% and 18%, respectively. These findings provide evidence for the prospect of using egg white-impregnated activated carbon for CO ₂ adsorption applications, which could lead to a new generation of affordable and eco-friendly adsorbents.