Low temperature oxidative template removal from SBA-15 using MnO4− solution and carbon replication of the mesoporous silica product

Abstract

We report a new method of low temperature removal of template from SBA-15 by KMnO₄ chemical oxidation. Using this silica as template, mesoporous carbon with thick pore walls and relatively small mesopores can be cast. The results from XRD and nitrogen sorption show that the silica obtained after surfactant removal has high surface area, high pore volume and good structural ordering. The obtained carbon replica also shows good structural ordering as reflected from XRD and TEM characterizations. EDX analysis shows that no residue of potassium and manganese in the carbon sample can be detected, indicating the complete removal of such species during the washing step. Interestingly, the analysis of the micropore volume based on the DFT method shows that these carbon replicas have a large fraction of micropores with respect to the total pore volume. These micropore rich carbon materials could be candidates as molecular sieve type adsorbents and catalyst supports.