Synergy in the Selective Production of Ketone Platform Compounds from Biomass Pyrolysis Vapors over CeO₂ Catalysts

Acetic acid, n-butyraldehyde, furfural, n-butanol, and ethyl acetate as model compounds of biomass pyrolysis vapors were selected as reactants for ketonization over CeO2. Catalytic conversion of single components was conducted to understand their ketonization characteristics and also to obtain the overlapped temperature range. The results showed that the yield of acetone from directional ketonization of acetic acid reached a maximum of 97.4% at 360 degrees C over CeO2 with numerous oxygen vacancies, while n-butyraldehyde, n-butanol, and ethyl acetate performed the best at 420 degrees C with limited yield of ketones of 47.2, 35.1, and 85.4%, respectively. At the overlapped 420 degrees C, owing to the dehydration of acetic acid molecules, the ketonization of n-butyraldehyde was promoted with the largest overall yield of ketones of 96.5%. A mixture of furfural/acetic acid (1:4) brought about a lower yield of ketones of 78.8%, indicating a negative synergism due to active sites occupation by furfural adsorption.