Magnesium oxide (MgO) is a promising candidate for carbon dioxide (CO2) capture at high temperature applicable to pre-combustion capture in an integrated gasification combined cycle (IGCC) scheme. In this work, mesoporous MgO nanoparticles were synthesized via simple complexation-combustion method by using glycine (G) and urea (U) as fuels (F). The obtained sorbents were thoroughly characterized in terms of the crystalline structure, morphology, nature of the fuel, F/O ratio, and their consequent effects on CO2 sorption. It was observed that due to the complexation followed by combustion in the presence of glycine, MgO with crystallite size as small as similar to 8 nm could be derived. The synthesized MgO nanoparticles exhibited exceptionally high CO2 sorption at elevated temperatures. Furthermore, CO2 sorption isotherms in assistance with FT-IR and DSC experiments demonstrated that the low CO2 uptake at ambient temperature (25-100 degrees C) may be due to the formation of monodentate carbonates, whereas predominant bicarbonates enhance the CO2 uptake at elevated temperatures (100-300 degrees C). MgO-1.5(G) obtained the highest sorption corresponding to 1.34 mmol/g at 200 degrees C. (C) 2017 Elsevier Inc. All rights reserved.