Removal of methyl–ethyl ketone vapour on polyacrylonitrile-derived carbon/mesoporous silica nanocomposite adsorbents

Mesoporous silica supports (MCM-41, SBA-15 and silica gel) were modified by the introduction of controlled amounts of polymer-derived carbon. Precipitation polymerization of polyacrylonitrile in the aqueous suspension of a silica material was used as a deposition method. The samples of PAN/silica composites were studied by thermal analysis, performed in air and inert atmosphere, in order to determine the amount of a deposited polymer and its thermal stability. The effect of surface area of a silica support and the monomer concentration in the mother solution on the effectiveness of deposition was revealed. The PAN/silica composites were transformed into C/SiO2 adsorbents by carbonization carried out at 623 K. Texture (low-temperature sorption of N2), surface structure (FTIR-DRIFT) and morphology (SEM) of the carbonized samples were investigated. The adsorption tests in the elimination of methyl–ethyl ketone from gas phase were performed under dynamic conditions. The MCM-41-based composites containing highly dispersed carbon layers on the surface appeared to be the most promising adsorbents for a commercial application. Moreover, these materials exhibited a high stability in the adsorption–desorption runs repeated ten times suggesting the possibility of regeneration of the adsorbent bed without a significant loss in the adsorption effectiveness.

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► Precipitation polymerization of acrylonitrile was proposed as a new deposition method.
► PAN deposited on mesoporous silicas was thermally transformed into the carbon layers.
► Carbon/silica composites appeared to be very effective adsorbents of VOCs.
► The developed adsorbents can be easily regenerated by thermal desorption of VOCs.