Abstract In order to counteract the greater level of green house gases including CO 2 , adsorption process has been found as one of the solution. Present work focuses on the high pressure CO 2 adsorption study of nanocomposite comprising of Pd nanoparticles decorated graphite nanoplatelets (GNP). Graphite nanoplatelets (GNP) were prepared by acid intercalation followed by thermal exfoliation. Functionalized graphite nanoplatelets (f-GNP) were prepared by further treatment of GNP in acidic medium. Palladium (Pd) nanoparticles were decorated over f-GNP surface by chemical method. Nanocomposite was characterized by electron microscopy, X-ray powder diffraction pattern, BET measurement, Raman spectroscopy and FTIR spectroscopy techniques. The CO 2 adsorption capacity was measured using high pressure Seiverts’ apparatus by incorporating van der Waals corrections and adsorption of CO 2 was confirmed by FTIR spectroscopy. A remarkable enhancement of 15–20% is obtained in CO 2 adsorption by decorating Pd nanoparticles over functionalized graphite nanoplatelets. Dubinin–Radushkevitch (DR) equation is applied to the adsorption isotherm at room temperature and the results have been discussed.