Rapid Preparation of Ultrafine BaSO₃ by SO₂ Storage Material

Abstract

In this work, a green and efficient process was developed for the preparation of ultrafine BaSO3 with layered nanostructure surface via the reaction of BaCl2 with a SO2 storage material (SO2SM) at room temperature. The absorption of SO2 with equimolar ethylenediamine (EDA) and ethylene glycol (EG) afforded SO2SM, which not only offered alkyl sulfite but also released EDA and EG that served as efficient surfactants to promote the formation of BaSO3 with spherical morphology and porous structure in the process of synthesis of ultrafine BaSO3. The factors affecting the morphology and size of BaSO3 particle were assessed by investigating the effects of SO2SM concentration, BaCl2 concentration, stirring time and speed. It was found that a higher SO2SM concentration led to a higher degree of supersaturation, and the particle size of BaSO3 could be reduced by increasing SO2SM concentration. Moreover, under the identified optimal reaction conditions, ultrafine BaSO3 was obtained with an average diameter of 450 nm. In addition, a plausible formation process of BaSO3 was proposed to explain the observed reaction results. Overall, the developed process in this work provides an efficient method for the capture, utilization, and conversion of SO2 into a valuable chemical.