Removal of low concentration CH₃SH with regenerable Cu-doped mesoporous silica

Mercaptans are highly volatile compounds responsible for disagreeable odors and very low olfactory threshold, especially for CH₃SH (0.4 ppvb). To the best knowledge of us, approach for controlling low-concentrated odors (i.e. 1-10 ppm) is scarcely reported. In this research, Cu-doped mesoporous silica was synthesized for removal of low-concentrated CH₃SH. The as-prepared samples show considerably thermal and mechanical stability and could be thermal-regenerated. Copper loading ratio and humidity have significant impacts on eliminating odors. According to XRD, TEM, BET, NMR and EPR, we deduce that surface groups on CuO nanoparticles and the SiOCu group are highly possibly transformed into a hydrated complex which is much more effective in capturing CH₃SH with its empty Cu-3d orbit. Although CH₃SH has to compete with water for absorption sites, it is always the "winner" owing to the strong chelating ability between SH group and Cu (Ⅱ).