Surface characterization studies on F-doped V2O5/TiO2 catalyst for NO reduction with NH3 at low-temperature

• Both kinds of F doping can improve the SCR reaction over the V2O5/TiO2 catalysts.
• F doping can improve the interaction of V2O5 with TiO2 by oxygen vacancies.
• The electrons in oxygen vacancies by F doping can be captured by V2O5 species.
• The reduced V2O5 species can improve the O2− formation.
• The O2− is the key for the NO oxidation to enhance the SCR reaction.

This study aimed at elucidating the surface characterization of F-doped V2O5/TiO2 catalyst to investigate the improvement of F doping for the catalytic activity in the SCR reaction at low-temperature. Analysis by PL spectra and DFT theoretical calculations showed that F doping improved the interaction of V species with TiO2 by oxygen vacancies and the electrons in oxygen vacancies were captured by V species. It could facilitate the formation of the reduced V species. The results of XPS, O2-TPD and EPR confirmed that the formation of the reduced V species, as well as the reduced V species were the active sites for the formation of superoxide ions. By the above process, NO oxidation was improved by F doping, which were beneficial for the SCR reaction. Moreover, the surface reaction characterization of VTiF catalyst was investigated that the nitrite and nitrate species of NO oxidation could react with Brönsted acid sites and Lewis acid sites over the F-doped V2O5/TiO2 catalyst.

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