Tunable Heterogeneous Catalysis: N-Heterocyclic Carbenes as Ligands for Supported Heterogeneous Ru/K-Al₂O₃ Catalysts To Tune Reactivity and Selectivity

Abstract

Here we report, for the first time, an extensive characterization of an N-heterocyclic carbene (NHC)-modified supported heterogeneous catalyst. The existence of the metal-carbene bond could be proven by (13)C-SS-NMR experiments. Furthermore, it could be shown that the modification with NHCs does not structurally change the catalyst itself. The effect of the nature and the loading of the NHC on the activity and selectivity of the heterogeneous catalyst is presented by a hydrogenation study, finally leading to an NHC-enabled tunable heterogeneous catalyst for chemoselective hydrogenation.

Solid-supported nitrogen acyclic carbene (SNAC) complexes of gold: Preparation and catalytic activity

“…As can be seen in Fig. 3, carbene N1s peaks correspond to those observed in a recently reported metal carbene complex (circa 400 eV) [12].…”

Ultra‐small and highly dispersed Pd nanoparticles inside the pores of ZIF‐8: Sustainable approach to waste‐minimized Mizoroki–Heck cross‐coupling reaction based on reusable heterogeneous catalyst

“…Accordingly, in recent years, an increasing number of studies have been focused on the utilization of NHCs as ligands for stabilizing nanoparticles. In this regard, NHCs have been successfully used for the stabilization of metal nanoparticles such as those of Ru, Pt, Au, Ni and Pd . NHCs can form strong covalent bonds with the surface of metal nanoparticles.…”

“…In this regard, NHCs have been successfully used for the stabilization of metal nanoparticles such as those of Ru, Pt, Au, Ni and Pd. [32,33] NHCs can form strong covalent bonds with the surface of metal nanoparticles.…”

N‐Heterocyclic Carbene‐Modified Au–Pd Alloy Nanoparticles and Their Application as Biomimetic and Heterogeneous Catalysts

“…[4][5][6] Until now,N HCs have been mainly applied for the stabilization of monometallic Au-, [7] Pd-, [7d,g,h, 8] Pt-, [9] and RuNPs. [10] Very recently,G lorius and co-workers reported the surfacem odification of supported Ru/K-Al 2 O 3 [11] and Pd/Al 2 O 3 [12] with NHC ligands. The coordination of carbenes on the metal NPs enabled the tuning of their chemoselectivity or even induced reactivity.…”