1 research outputs found
Understanding the Catalytic Active Sites of Crystalline CoSb<sub><i>x</i></sub>O<sub><i>y</i></sub> for Electrochemical Chlorine Evolution
The chlorine evolution reaction (CER) is a key reaction
in electrochemical
oxidation (EO) of water treatment. Conventional anodes based on platinum
group metals can be prohibitively expensive, which hinders further
application of EO systems. Crystalline cobalt antimonate (CoSbxOy) was recently
identified as a promising alternative to conventional anodes due to
its high catalytic activity and stability in acidic media. However,
its catalytic sites and reaction mechanism have not yet been elucidated.
This study sheds light on the catalytically active sites in crystalline
CoSbxOy anodes
by using scanning electrochemical microscopy to compare the CER catalytic
activities of a series of anode samples with different bulk Sb/Co
ratios (from 1.43 to 2.80). The results showed that Sb sites served
as more active catalytic sites than the Co sites. The varied Sb/Co
ratios were also linked with slightly different electronic states
of each element, leading to different CER selectivities in 30 mM chloride
solutions under 10 mA cm–2 current density. The
high activity of Sb sites toward the CER highlighted the significance
of the electronic polarization that changed the oxidation states of
Co and Sb