Acetone synthesis from ethanol and the Mars and Van Krevelen mechanism using CeO2 and AgCeO2 nanostructured catalysts

Nanostructured CeO2 based catalysts were employed as tools to shed light on the mechanism of the acetone synthesis from ethanol. The oxides were characterized using HRTEM, EPR, and other techniques. Rates of ethanol consumption and products formation were measured at differential conditions. The catalysts prepared employing Ce(NO3)(3) generate nanocubes, whereas when (NH4)(2)Ce(NO3)(6) is used, nanopolyhedral particles are synthesised. The later forms O vacancies more easily. This property enhances when Ag is added to the nanopolyhedral catalyst. The correlation between the catalytic behaviour and the nanocatalysts's physicochemical properties showed that O vacancies participate as Brunsted basic sites in the acetaldehyde synthesis and that the easier the O vacancies generation, the higher the rate of the acetone synthesis is. The O abstraction from the CeO2 lattice by acetaldehyde (Mars and Van Krevelen mechanism) is the slowest step of the acetone synthesis from ethanol, showing that this synthesis exhibits a relevant redox characteristic.

Automated summary

Nanostructured CeO2 based catalysts were used to investigate the mechanism of acetone synthesis from ethanol. It was found that O vacancies play a crucial role in the reaction, with easier generation of O vacancies leading to higher acetone synthesis rates.