Partially Reduced Tin Oxide As a Selective Electrochemical Ozone Production Catalyst
Authors: Alaufey Rayan , Tang Maureen H. 
Published: December 2024

Rapid global urbanization has created a pressing need for clean and accessible water supplies. Traditional water treatment methods are often limited by the increasing demands and complexities associated with human population growth.1–3A critical factor widening the gap between industrial progress and environmental sustainability is the inability of current technologies to effectively address the growing issue of water contamination.4,5 Advancements in electrochemical water treatment methods could provide a promising path towards bridging this gap and offer sustainable solutions to global water scarcity.
Among water treatment methods, the 6-electron electrochemical ozone production (EOP) reaction stands out. EOP offers a significant advantage because it allows for the on-site generation of ozone (O3), a powerful oxidizer with a minimal environmental footprint compared to other disinfectants.6 Nickel and antimony doped tin oxide (Ni/Sb-SnO2) is one of the most selective catalysts for EOP under normal operating conditions.7–10 Our previous work suggested that the primary function of antimony (Sb) in this catalyst is to enhance the electrical conductivity, which is crucial for optimal electrochemical performance. Conversely, the catalytic activity for EOP has been attributed to the presence of nickel (Ni) dopants. 9,11–13 Interestingly, the presence of n-type dopants, such as Sb, can cause catalyst instability.12,14

Herein, we explore a promising alternative approach to n-type doping: partial reduction of the catalyst. By partially reducing tin oxide, we can potentially achieve the desired conductivity enhancement without the drawbacks associated with destabilizing the catalyst. . In this work, through a combination of electroanalysis and spectroscopic detection of ozone, we confirm the selectivity of partially reduced tin oxides towards EOP. Furthermore, we employ various methods to rigorously assess the stability of this novel catalyst. Our findings establish a framework for the development of improved EOP catalysts with superior performance. This could potentially pave the way for significant advancements in the field of electrochemical water treatment.
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