Hydrogenative Ring-Rearrangement of Furfural to Cyclopentanone over Pd/UiO-66-NO2 with Tunable Missing-Linker Defects

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 19; p. 5736
• Main Authors: Wang, Chunhua, Yu, Zhiquan, Yang, Yuhao, Sun, Zhichao, Wang, Yao, Shi, Chuan, Liu, Ying-Ya, Wang, Anjie, Leus, Karen, Van Der Voort, Pascal
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 22.09.2021; MDPI
• Subjects: Acids; cyclopentanone; Diffraction; double-solvent method; furfural; Hydrogenation; hydrogenative ring-rearrangement; Morphology; Nanoparticles; Pd/UiO-66-NO2; Pore size
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26195736

Upgrading furfural (FAL) to cyclopentanone (CPO) is of great importance for the synthesis of high-value chemicals and biomass utilization. The hydrogenative ring-rearrangement of FAL is catalyzed by metal-acid bifunctional catalysts. The Lewis acidity is a key factor in promoting the rearrangement of furan rings and achieving a high selectivity to CPO. In this work, highly dispersed Pd nanoparticles were successfully encapsulated into the cavities of a Zr based MOF, UiO-66-NO2, by impregnation using a double-solvent method (DSM) followed by H2 reduction. The obtained Pd/UiO-66-NO2 catalyst showed a significantly better catalytic performance in the aforementioned reaction than the Pd/UiO-66 catalyst due to the higher Lewis acidity of the support. Moreover, by using a thermal treatment. The Lewis acidity can be further increased through the creating of missing-linker defects. The resulting defective Pd/UiO-66-NO2 exhibited the highest CPO selectivity and FAL conversion of 96.6% and 98.9%, respectively. In addition, the catalyst was able to maintain a high activity and stability after four consecutive runs. The current study not only provides an efficient catalytic reaction system for the hydrogenative ring-rearrangement of furfural to cyclopentanone but also emphasizes the importance of defect sites.