Controlling Multiple Active Sites on Pd−CeO2 for Sequential C−C Cross‐coupling and Alcohol Oxidation in One Reaction System

• Published in: ChemCatChem 2022-02, Vol.14 (4), p.n/a
• Main Authors: Ko, Wonjae, Kim, Ju Hee, Yim, Guk Hee, Lee, Seong Chan, Kim, Sumin, Kwak, Minjoon, Choi, Hyunwoo, Kim, Jongchan, Antink, Wytse Hooch, Kim, Jiheon, Lee, Chan Woo, Bok, Jinsol, Jung, Yoon, Lee, Eunwon, Lee, Kug‐Seung, Cho, Sung‐Pyo, Kim, Do Heui, Kim, Young Gyu, Lee, Byoung‐Hoon, Hyeon, Taeghwan, Yoo, Dongwon
• Format: Article
• Language: English
• Subjects: Active control; Catalysts; Cerium oxides; Cross coupling; Heterogeneous catalysis; Multicomponent reactions; Nanoclusters; Optimization; Oxidation; Palladium; Supported catalysts
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.202101760

Ceria (CeO2)‐supported metal catalysts have been widely utilized for various single‐step chemical transformations. However, using such catalysts for a multistep organic reaction in one reaction system has rarely been achieved. Here, we investigate multiple active sites on Pd−CeO2 catalysts and optimize them for a multistep reaction of C−C cross‐coupling and alcohol oxidation. Atomic‐level imaging and spectroscopic studies reveal that metallic Pd0 and Pd−CeO2 interface are active sites on Pd−CeO2 for C−C cross‐coupling and oxidation, respectively. These active sites are controlled under the structural evolution of Pd−CeO2 during reductive heat‐treatments. Accordingly, we found that optimally reduced Pd−CeO2 catalysts containing ∼1.5 nm‐sized Pd nanoclusters with both sites in balance are ideal for multistep chemical transformations in one reaction system. Our strategy to design supported metal catalysts leads to one‐pot sequential synthetic protocols for pharmaceutical building blocks. Multistep organic reaction of C−C cross‐coupling and alcohol oxidation is achieved on the heterogeneous surface of CeO2‐supported Pd catalyst. Atomic‐level imaging and spectroscopic studies reveal that metallic Pd0 and Pd−CeO2 interface are the active sites for C−C cross‐coupling and alcohol oxidation, respectively. Furthermore, these active sites on Pd−CeO2 were effectively controlled by reductive heat‐treatment, which leads to the optimal structure of Pd−CeO2 for the multistep reaction in one reaction system.