Poly(tetrafluoroethylene)-Stabilized Metal Nanoparticles: Preparation and Evaluation of Catalytic Activity for Suzuki, Heck, and Arene Hydrogenation in Water

Atsushi Ohtaka; Misa Kawase; Shunichiro Aihara; Yasuhiro Miyamoto; Ayaka Terada; Kenta Nakamura; Go Hamasaka; Yasuhiro Uozumi; Tsutomu Shinagawa; Osamu Shimomura; Ryôki Nomura

doi:10.1021/acsomega.8b01338

Poly(tetrafluoroethylene)-Stabilized Metal Nanoparticles: Preparation and Evaluation of Catalytic Activity for Suzuki, Heck, and Arene Hydrogenation in Water

ACS Omega. 2018 Aug 29;3(8):10066-10073. doi: 10.1021/acsomega.8b01338. eCollection 2018 Aug 31.

Authors

Affiliations

¹ Department of Applied Chemistry, Faculty of Engineering, and Nanomaterials and Microdevices Research Center, Osaka Institute of Technology, 5-16-1 Ohmiya, Asahi, Osaka 535-8585, Japan.
² Institute for Molecular Science (IMS), Higashiyama 5-1, Myodaiji, Okazaki 444-8787, Japan.
³ Electronic Materials Research Division, Morinomiya Center, Osaka Research Institute of Industrial Science and Technology, Joto-ku, Osaka 536-8553, Japan.

Abstract

Poly(tetrafluoroethylene)-stabilized Pd nanoparticles (PTFE-PdNPs) were prepared in water with 4-methylphenylboronic acid as a reductant and characterized using powder X-ray diffraction, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Small PdNPs with a fairly uniform size were obtained in the presence of PTFE, whereas aggregation of palladium was observed in the absence of PTFE. PTFE-PdNPs showed high catalytic activity for the Suzuki coupling reaction in water and were reused without any loss of activity. No palladium species were observed by ICP-AES analysis in the reaction solution after the reaction, nor was any change in particle size observed after the recycle experiment. PTFE-PdNPs also exhibited excellent catalytic activity and reusability for the Heck reaction in water. Although palladium species were not detected in the reaction solution after the reaction, aggregates and smaller sizes of PdNPs were observed in the TEM image of the recovered catalyst. PTFE was also useful as the stabilizer of rhodium nanoparticles (RhNPs) prepared by reduction with NaBH₄. PTFE-RhNPs showed high catalytic activity and reusability toward arene hydrogenation under mild conditions.