Efficient Cu/CeO<sub>2</sub> for Ketonization of Carboxylic Acids with Synergistic Interactions
Shan Zhang, Binbo Jiang, Ming‐Liang Tong, Yao Yang, Zuwei Liao, Zhengliang Huang, Jingyuan Sun, Jingdai Wang, Yongrong Yang
Abstract
Cost-effective heterogeneous catalysts are critical to the ketonization of carboxylic acids for producing biofuels and platform chemicals. Herein, nanocrystalline Cu-loaded CeO 2 with 1.0–9.0 wt % Cu loadings was synthesized by the precipitation-impregnation method, in which 3.0 wt % Cu/CeO 2 exhibits the best performance of 72% acetone yield at 330 °C, 97% 3-pentanone yield at 360 °C, and 86% 4-heptanone yield at 400 °C, with good durability up to 10 h on stream. Detailed analyses reveal that 3.0 wt % Cu/CeO 2 has the highest percentage of O-vacancy sites, more moderate acid–base sites, and better capacity to adsorb and activate carboxylic acids. In situ DRIFT spectra indicate that monodentate, bridging bidentate, and chelating bidentate modes coexist when carboxylic acid is dissociatively adsorbed on 3.0 wt % Cu/CeO 2 . Based on the above investigations, we propose a mechanism over 3.0 wt % Cu/CeO 2 through the β-ketoacid intermediate route, which gives more details to help future research into the design and development of catalysts for ketonization.