The identification of the crystalline phases of the zeolite sam- ples was performed by x-ray diffractometry in a Rigaku (DMAXB) X-ray Powder Diffractometer by using a Bragg–Brentano geom- etry. X-ray photoelectron spectroscopy (XPS) was carried out to determine the atomic concentrations (%) of the elements on the sur- face of the pristine and amine-impregnated samples, especially the atomic concentration % of nitrogen induced by the chemical mod- ification. Spectra were obtained at ultra high vacuum (10−12 bar) using a Physical Electronics spectrometer (model 5700). Thermo- gravimetric analyses (TGA) were carried out using as Shimadzu TGA 50 equipment, with a heating rate of 10 K/min, in a dynamic N2 atmosphere with approximately 5.0 mg sample. The temperature range of 340–1000 K was used for TGA analyses. FTIR spectra were obtained using a Bruker IFS88 spectrometer and specially designed cells which were permanently connected to a gas or vacuum line. Spectra were obtained at two temperatures (298 and 348 K) and two pressures (vacuum and 1 bar pure CO2 ).