Gold nanoparticles (Au NPs) functionalized with N-heterocyclic carbene (NHC) ligands immobilized onto graphene are obtained via spontaneous decomposition of well-defined gold-NHC complexes by reduced graphene oxide (rGO) without reducing agents. NHC ligands are responsible for the formation of air-stable, crystalline and small (3.0-4-0 nm) Au NPs homogeneously distributed on the surface of graphene. The catalytic properties of three Au NPs functionalized with different ligands were tested in two benchmark reactions (hydration of alkynes and intramolecular hydroamination of alkynes). The results reveal a pronounced ligand effect on the stability of Au NPs on graphene, by acting as a bridge between them. The Au NPs functionalized with a NHC ligand lacking a polyaromatic group or having a naphthyl tag displayed limited stability and fast deactivation in the first run. On the contrary, the Au NPs functionalized with a NHC ligand containing a pyrenyl handle showed superior catalytic activity and can be recycled at least ten times. The particle size of the Au NPs is preserved after the recycling process indicating a high stability. These results illustrate the use of purposely designed ligands having affinity for both Au NPs and graphene to increase the stability of the hybrid catalyst.

借助固定的石墨烯上的N杂环卡宾（NHC）配体官能化的金纳米颗粒（Au NP），是通过还原型氧化石墨烯（rGO）自发分解明确定义的金-NHC复合物而无需还原剂而获得的。NHC配体负责形成均匀分布在石墨烯表面的空气稳定的，结晶的和小的（3.0-4-0 nm）Au NP。在两个基准反应（炔烃的水合和炔烃的分子内加氢胺化）中测试了用不同配体官能化的三个Au NP的催化性能。结果表明，通过充当它们之间的桥梁，配体对Au NP在石墨烯上的稳定性有明显的影响。用缺乏多芳族基团或具有萘基标签的NHC配体官能化的Au NP在第一轮中显示出有限的稳定性和快速的失活。相反，被含有a基手柄的NHC配体官能化的Au NPs显示出优异的催化活性，可以循环使用至少十次。循环处理后，Au NPs的粒径得以保留，表明具有很高的稳定性。这些结果说明了使用对金纳米颗粒和石墨烯均具有亲和力的专门设计的配体，以提高杂化催化剂的稳定性。循环处理后，Au NPs的粒径得以保留，表明具有很高的稳定性。这些结果说明了使用对金纳米颗粒和石墨烯均具有亲和力的专门设计的配体，以提高杂化催化剂的稳定性。循环处理后，Au NPs的粒径得以保留，表明具有很高的稳定性。这些结果说明了使用对金纳米颗粒和石墨烯均具有亲和力的专门设计的配体，以提高杂化催化剂的稳定性。