Synthesis of pseudo-CMK-3 carbon replicas by precipitation polycondensation of furfuryl alcohol in the pore system of SBA-15 detemplated using KMnO4

Abstract

The parameters of liquid-phase detemplation of SBA-15 using KMnO4 were optimized. The resultant silica with different textural and structural characteristic compared to that obtained by calcination, was employed for the synthesis of a series of carbon replicas using precipitation polycondensation of furfuryl alcohol. As a counterpart, the typical CMK-3 replica based on calcined silica was synthesized. The application of mild-detemplated SBA-15 resulted in the formation of pseudo-CMK-3 structures that differed from typical CMK-3 in the higher microporosity, thicker walls and lack of narrow carbon spacers, typically formed in calcined matrix. The primary mesopores of pseudo-CMK-3 were accompanied by the broader mesochannels formed by the coalescence of SBA-15 pores unfilled fully with the carbon precursor. The pseudo-CMK-3 materials could be excellent candidates either for modeling of adsorption and diffusion phenomena in solids with a bimodal mesopore-size distributions or adsorption and catalysis purposes. An attempt was made to elucidate the mechanism of deposition of poly(furfuryl alcohol) onto SBA-15. A new approach to assessing the fidelity of replica architecture in regard to pristine silica was proposed. Finally, it was found that the carbon bridges formed in the interconnecting micropores of SBA-15 do not play a crucial role in merging of replica framework, as was hitherto believed.