Novel cobalt-based MOF facilitating reclaiming byproduct in wet magnesia desulfurization with ultrahigh dispersity and catalytic activity

Abstract

In the wet magnesia desulfurization process, magnesium sulfite oxidation is essential to reclaim and resource utilization the byproducts. Therefore, it is of great significance to create reliable and effective catalysts. In this study, a novel and efficient catalyst, Co-MOF (BTC), was synthesized by an ultrasound assisted one-pot method. The oxidation rate of MgSO3 by Co-MOF (BTC) was 0.112 mmol·L−1·s−1, 13–14 times higher than under non-catalytic conditions, with an apparent activation energy of 26.82 kJ·moL−1. The catalytic efficiency is 4–5 times higher than previously reported Co-SBA-15 catalysts with the same loading. The characterization results of XRD, TEM and XPS confirm that the active component cobalt has a high dispersion on TMLA, and Co (II) plays an important role in improving the oxidation performance of catalysts. The results reveal that the rich hydroxyl group on surface of TMLA is conducive to the dispersion of Co for full contact with the reactants, and the Co (II) of Co-MOF (BTC) is favorable to the formation of Co-O bond, and then promotes its oxidative activity. The kinetics of the MgSO3 oxidation catalyzed by the prepared Co-MOF (BTC) was investigated in a bubble oxidation apparatus, indicating that the oxidation rate was dependent on the reaction temperature, pH value, oxygen partial pressure and air velocity.