Formation and structural characterization of potassium titanates and the potassium ion exchange property

In the present work, K2Ti2O5, K2Ti4O9 and K2Ti6O13 are synthesized by solid state method. Their structures and morphologies are characterized by X-ray diffraction, Raman spectra and scanning electron microscopy. The binding energies of K, Ti and O in potassium titanates were then evaluated by X-ray photoelectron spectroscopy and compared with those in K/TiO2. Finally the corresponding K ion exchange properties are investigated by synthesizing NO oxidation catalysts with Co(NO3)2 precursor. It is found that the binding energy of K in K2Ti2O5 is much higher than those in K2Ti4O9 and K2Ti6O13, and because of which, it shows quite different catalytic performances. Compared with other potassium titanates, the K in K2Ti2O5 is much easier to be exchanged out.