(208c) Tuning Surface Properties of Titanium Dioxide for Carbon Monoxide Oxidation over Copper-Titanium Dioxide

Copper catalysts, either un-supported or supported on an oxide, have been explored for carbon monoxide reactions for decades[1]. Studies under high vacuum conditions suggested that low valent copper species, particularly Cu(I), has a comparable reaction rate as other precious metals[2]. Meanwhile, the oxidation states and active sites of copper became complicated once copper species were supported on reducible metal oxides, including titanium dioxide. We used copper-titanium dioxide as the platform to investigate the relationship between the surface properties of titanium dioxide and their activities in the carbon monoxide oxidation reaction. Commercial P25 titanium dioxide was modified through two different approaches: i) tuning the surface basicity with the aid of sodium hydroxide; and ii) modifying the surface with nitrogen. Our results revealed that both approaches would improve copper dispersion and increase the concentration of surface oxygen vacancies. We also found that the reaction rate in carbon monoxide oxidation was determined by the abundance of Cu(I)-O(surf.) clusters on the surface[3].

References

[1] S. Royer, D. Duprez, ChemCatChem 3 (2011) 24.

[2] G.G. Jernigan, G.A. Somorjai, J.Catal. 147 (1994) 567.

[3] G.Q. Cao, N. Yi, Revised (2019).