Metal doped manganese oxide octahedral molecular sieve catalysts for degradation of diclofenac in the presence of peroxymonosulfate

Abstract

Manganese oxide octahedral molecular sieve (OMS-2) and a series of OMS-2 doped with Co, Cu, and Ce were prepared via a solvent-free method, and tested in heterogeneous activation of peroxymonosulfate (PMS) for diclofenac (DCF) degradation in aqueous solutions. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), N2 adsorption/desorption isotherms, Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-ray photoelectron spectroscopy (XPS) were used to characterize the properties of those materials. It was found that (Co + Ce)-OMS-2 seemed to be most efficient and had the best adsorption capacity, which may due to most abundant lattice oxygen and more macropore than other materials caused by cerium ions enter into the channel. Results from XPS suggested that the highly catalytic efficiency possible involved the activation of PMS to sulfate and hydroxyl radical meditated by the redox pair of Mn(IV)/Mn(III) and Co(III)/Co(II) in catalysts.