“…The BET results reveal that the surface area, pore volume, and pore size of pure silica are 123.85 m 2 g −1 , 28.46 cm 3 g −1 , and 13.97 nm, respectively, and those of the silica impregnated with CO are 5.09 m 2 g −1 , 1.17 cm 3 g −1 , and 11.9 nm, respectively. The lower values in the latter case imply that due to the impregnation of CO into the pores of silica, only a little amount of N 2 is adsorbed onto the pores of the SiCO during the BET test . The impregnation of CO in the pores of silica is clear from the EDX spectra shown in Figure (a–c).…”