Construction of lattice-confined Co-MCM-48 for boosting sulfite oxidation in wet desulfuration

Abstract

Magnesium sulfite oxidation is a crucial process in wet desulfurization which inhibits the re-emission of SO2 efficiently, and the development of catalyst with high activity and stability is still a challenge. In this study, a lattice confined Co-based catalyst was constructed through the in situ growth of Co active sites in MCM-48 molecular sieves (Co-MCM-48). The anchoring of separated Co sites in MCM-48 matrix favored to enhance the MgSO3 oxidation and inhibit the leaching of Co element. From the atom-level, the sulfite adsorption was enhanced on the isolated and defected Co sites, and the SO3− intermediate was considerably easy to generate due to the enhanced loss of electrons in sulfite. Meanwhile, the adsorption of O2 was improved by Co-MCM-48, and the adsorbed O2 (O2(ad)) accelerated the production of SO5− radical by the process of SO3− + O2(ad) → SO5−, which play key roles for the fastened oxidation of MgSO3.