(560fo) Mechanistic Study of Water Oxidation to Ozone on Rutile SnO2 (110) with Computational Chemistry

Producing clean water to sustain the population remains challenged with increasing demand. Ozone disinfects water sources from certain bacteria with little environmental trace due to its low residence time in water. While reliable, ozone is difficult to produce. Electrochemical ozone production (EOP) by means of direct water-to-ozone conversion is a potential competitor to cold corona production, a common but inefficient approach, but EOP also faces limited efficiency due to high overpotentials. Understanding the mechanism of water-to-ozone conversion on heterogeneous catalysts gives insight into the overpotentials in EOP and directs searches for proper catalysts to optimize this process. Here, we investigate thermodynamic descriptors of viable reaction steps on rutile SnO₂ (110) surface models with Kohn-Sham density functional theory (KS-DFT) calculations according to the computational hydrogen electrode model. These descriptors are used to build Pourbaix diagrams that show the stability of each step, as a function of pH and applied potential, and suggest routes to improve the catalytic active sites within SnO₂. Finally, we apply and assess our mechanistic findings on SnO­₂ surfaces doped with Ni and Sb as a catalyst candidate for improved EOP.