Surface and pore structures of CMK-5 ordered mesoporous carbons by adsorption and surface spectroscopy

Abstract

Ordered mesoporous carbons (OMCs) were synthesized in the pore system of SBA-15 aluminosilicates with different Si/Al ratios ranging from 5 to 80. Nitrogen adsorption was used to characterize the pore structure of the aluminosilicates and of the OMCs, whereas the OMC surface chemistry was studied by X-ray photoelectron spectroscopy and static secondary ion mass spectroscopy. The results indicate that the physicochemical properties of the OMCs depended significantly on the acid catalytic activity of the aluminosilicate frameworks, which comes along with the variation of Si/Al ratios. The OMC pore widths and order of the graphene layers followed the same trend as the catalytic activity of the aluminosilicates, whereas the concentration of extraframework species in the aluminosilicates indirectly influenced the mechanical properties of the OMCs. The reasons for this behavior are discussed.