Hydrophobic copper doped ceria-based catalyst for ketonization of acetic acid by suppressing water inhibition

Abstract

Hydrophobizing the surface of catalysts is essential in many catalytic reactions confined by water, but it can be quite challenging for metal oxide catalysts because of their intricate structure and surface properties. Herein, a series of hydrophobic copper doped ceria-based catalysts was synthesized by introducing stearic acid over the surface of catalysts for the ketonization of acetic acid co-feeding with different concentration of water. Detailed investigations reveal that the stearic acid functionalization process obviously improves the hydrophobicity of Cu/CeO2 without greatly changing their structures. Due to the excellent hydrophobicity to inhibit water in the reaction system, ketonization activities of acetic acid were greatly improved over the hydrophobic Cu/CeO2 catalysts co-feeding with 10–65 mol.% water. Specifically, the acetic acid conversion and acetone yield reached 94 % and 87 % co-feeding with 47 % mol.% water at 330 °C over Cu/CeO2-2, respectively, outperforming stearic acid-free catalyst under the same conditions. Besides, the hydrophobic Cu/CeO2 catalyst was with good durability up to 10 h on stream. The promotion of catalytic activities gives more details to help future research into the design and development of catalysts for future industrial applications of ketonization.