Copper(II) oxide (CuO) nanoparticles (NPs) in two different morphologies, spiky and spherical, were synthesized on zeolite-Y by a modified impregnation method, and their CO2 adsorbing capabilities were investigated under standard conditions (1 atm and 298 K). The properties and CO2 adsorption performances of the hybrid systems were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, atomic absorption spectroscopy, and Brunauer-Emmett-Teller analyses. The microscopy analyses showed that spiky nanostructures have a length of approximately 450 nm, and the spherical ones are approximately 18 nm in diameter. Quantitative analyses demonstrated that CuO NPs in both morphologies on the zeolite surface led to an improvement in their CO2 adsorption capacities. This enhancement is mainly due to the higher CO2 chemisorption capability of CuO NP-zeolite systems compared to that of bare zeolite. The presence of spiky and spherical CuO NPs on the zeolite surface resulted in increases of 112% and 86% in the amount of chemisorbed CO2 on the zeolite-Y surfaces, respectively.