PI: Jonas Baltrusaitis
Co-PI: Asal Saeidfar
University: Lehigh University
Industry partner: CDG Environmental, LLC
Sodium chlorite (NaClO2) is extensively used as a precursor for on-site chlorine dioxide (ClO2) generation. ClO2, in turn, is used for water treatment and industrial bleaching since it results in less corrosion to equipment and generates less harmful disinfection, reducing environmental and health risks. For these reasons, ClO2 is preferable over conventional strong oxidants, such as sodium hypochlorite (NaOCl) or chlorine gas (Cl2). Industrially, NaClO2 is synthesized by the reduction of sodium chlorate (NaClO3) in an acidic solution. However, these synthesis methods are extremely energy-consuming and environmentally while NaClO3 poses safety concerns in transport and storage. More sustainable and economically viable feedstocks of NaClO2 to produce the final ClO2 product are needed.
Industrial partners at CDG Environmental, LLC have an abundant supply of NaOCl and need its selective electrochemical oxidation into NaClO2, which is already their common feedstock for the final ClO2 product production. While feasible thermodynamically, NaOCl oxidation to NaOCl2 will compete with the oxygen evolution reaction (OER), which has a lower onset potential on these conventional catalysts. The selectivity and the overall Faradaic efficiency can be potentially tuned using proposed electrode materials, which do not generate chemisorbed hydroxyl group (OH) intermediates and hence suppress OER until high potentials of ~2.2 V. The proposed work will devise such catalysts and test them to optimize the conditions for 10 g/l NaClO2 production.