Engineering porous clay nanoarchitectures from unusual commercial organoclay: Supported manganese oxide as stable catalysts in the total oxidation of volatile organic compounds

Abstract

The porous engineering of clay nanoarchitectures (PCN) achieved from a well-known but little-explored commercial organoclay C-20A is reported. Thorough characterizations (by XRD, TGA, N₂ sorption, ICP, SEM, TEM, ²⁷Al MAS NMR, DR UV-Vis, XPS, Py-FTIR and H₂-TPR) confirmed a delaminated structure presenting a specific surface area of 504 m² g⁻¹, twelve times higher than the sodic montmorillonite used as reference and featuring a new pore system comprising a size range from supermicropores to small mesopores (1.3–10 nm). The role of these PCN as support of manganese oxide for the gas-phase total catalytic oxidation of volatile organic compounds (VOCs) was evaluated. PCN with 5 % of Mn resulted in a higher nanoparticle dispersion (10 nm) compared to the sodic montmorillonite (17 nm). The highest catalytic activity was reached with PCN containing 10 % of Mn achieving a benzene, toluene and ortho-xylene oxidation of 54 %, 39 % and 34 %, respectively, at 350 °C. The catalyst was stable up to 36 h under these conditions.