Characterization of VOx-TiO2 catalysts and their activity in the partial oxidation of methyl ethyl ketone

The present work focuses on the partial oxidation of methyl ethyl ketone to acetic acid over TiO2 supported vanadia catalysts with V loadings from 1 to 13.5 wt.%. In order to elucidate the relation between catalytic activity and the structure of the catalysts, the catalysts were also characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction with hydrogen (TPR), and temperature programmed desorption of lattice oxygen (TPD-O2). The investigations show that with increasing V loading the MEK conversion increased whereas the turn-over frequency decreased. At lower V loading (1–4 wt.%) the total oxidation to COx was favoured and the selectivities to acetic acid and other oxygenated products were low. The highest selectivities to acetic acid were achieved at V loadings of 4–6 wt.%. Based on literature data and our results, a scheme of the reaction pathways for the partial oxidation of MEK to AcOH and other by-products was developed.

Graphical abstractThe present work focuses on the partial oxidation of methyl ethyl ketone to acetic acid over TiO2 supported vanadia catalysts with V loadings from 1 to 13.5 wt.%. The investigations showed that with increasing V loading the rate of MEK conversion increased whereas the turn-over frequency decreased (Fig. 7). The highest selectivities to acetic acid were achieved at V loadings of 4–6 wt.%.Figure optionsDownload full-size imageDownload as PowerPoint slide