Single-site metal–organic framework catalysts for the oxidative coupling of arenes via C–H/C–H activation. Issue 12 (22nd February 2019)

• Record Type: Journal Article
• Authors: Van Velthoven, Niels; Waitschat, Steve; Chavan, Sachin M.; Liu, Pei; Smolders, Simon; Vercammen, Jannick; Bueken, Bart; Bals, Sara; Lillerud, Karl Petter; Stock, Norbert; De Vos, Dirk E.
• Is Part Of: Chemical science. Volume 10:Issue 12(2019)
• Page Start: 3616
• Page End: 3622
• Publication Date: 2019-02-22
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8sc05510f
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Heterogeneous palladium single-site MOF catalysts for the oxidative coupling of arenes via C–H/C–H: superior TONs due to active site isolation. Abstract : C–H activation reactions are generally associated with relatively low turnover numbers (TONs) and high catalyst concentrations due to a combination of low catalyst stability and activity, highlighting the need for recyclable heterogeneous catalysts with stable single-atom active sites. In this work, several palladium loaded metal–organic frameworks (MOFs) were tested as single-site catalysts for the oxidative coupling of arenes ( e.g. o -xylene) via C–H/C–H activation. Isolation of the palladium active sites on the MOF supports reduced Pd(0) aggregate formation and thus catalyst deactivation, resulting in higher turnover numbers (TONs) compared to the homogeneous benchmark reaction. Notably, a threefold higher TON could be achieved for palladium loaded MOF-808 due to increased catalyst stability and the heterogeneous catalyst could efficiently be reused, resulting in a cumulative TON of 1218 after three runs. Additionally, the palladium single-atom active sites on MOF-808 were successfully identified by Fourier transform infrared (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy.