Solid supported or ligand capped gold nanomaterials (AuNMs) emerged as versatile and recyclable heterogeneous catalysts for a broad variety of conversions in the ongoing catalytic ′gold rush′. Existing at the border of homogeneous and heterogeneous catalysis, AuNMs offer the potential to merge high catalytic activity with significant substrate selectivity. Owing to their strong binding towards the surface atoms of AuMNs, NHCs offer tunable activation of surface atoms while maintaining selectivity and stability of the NM even under challenging conditions. This work summarizes well‐defined catalytically active NHC capped AuNMs including spherical nanoparticles and atom‐precise nanoclusters as well as the important NHC design choices towards activity and (stereo‐)selectivity enhancements.

No abstract

Hollow mesoporous silica particles (HMSPs) have recently drawn much attention as nanocatalysts, owing to their benefits and potential for greener chemical processes. Here, improved synthesis of HMSPs exhibiting a shell with a 3‐D pore structure is proposed to overcome previous synthetic issues, such as reproducibility, particle size distribution, precise tailoring of size/shell thickness, low yield, etc. Additionally, precisely controlled and selective functionalization with amine groups is achieved owing to careful protection and sequential extraction protocols. To overcome time‐consuming and complex multistep extraction procedures, different methods were optimized towards the most efficient protocol. The obtained materials are characterized in terms of structure, porosity and functions, and the confined catalytic activity was tested in a Knoevenagel reaction. The nanocatalysts were compared before and after the core template was removed to confirm that the only catalytic species are free amines located on the inner external surface of the shell (i. e., the surface exposed towards the hollow core).

The bottom-up synthesis of plasmonic NHC@CuNPs from common starting reagents, via the formation of the synthetically accessible NHC-Cu(I)-Br complex and its reduction by NH3·BH3 is reported. The resulting NHC@CuNPs have...

Highly active and selective heterogeneous catalysis driven by metallic nanoparticles relies on a high degree of stabilization of such nanomaterials facilitated by strong surface ligands or the deposition on solid...