The increasing concentration of carbon dioxide in the atmosphere has been pointed out as one possible causer of climate changes, what has been encouraging the rising number of studies about means to reduce the level of this gas in the atmosphere. The purpose of this work is to develop nanosized materials that can be used as CO2 sorbents in mild operational conditions. Starting with the assessment of some preselected capture processes, materials that have affinity with this gas were synthesized and characterized, presenting high surface area and basic sites. Thus, calcium and magnesium oxides were produced using nitrates as precursors in a technique of precipitation in aqueous solution and calcination. These oxides were analyzed using DRX and MEV/EDS techniques, defining the elementary chemical composition and the morphology of their surfaces. Surface areas were defined by BET method, as 34 m2/g for MgO, 19 m2/g for CaO and 26 m2/g for the mixed oxides MgO/CaO, and the particle diameters were estimated, characterizing them as nanosized materials. Finally, TPD tests were made, evaluating the sorption capacity of the synthesized materials in preselected conditions and their viability in the adsorption of carbon dioxide. The results obtained were 103 micromol/g for MgO, 126 micromol/g for CaO and 319 micromol/g for the mixed oxides MgO/CaO, being possible to conclude that the proposed process is technically viable, comparing these results with the ones found in the previously analyzed works.