Synthesis of an amino-functionalized metal-organic framework at a nanoscale level for gold nanoparticle deposition and catalysis

In this study, highly dispersed Au nanoparticles have been immobilized on amino-functionalized metal-organic frameworks (MOFs) via a novel absorption/reduction method in solution. The amino functionality of the MOF rapidly coordinated with HAuCl4 and acted as the Au(0) precursor in the absence of protecting agents. The resulting Au@MOF catalyst was well dispersed in aqueous media taking advantage of its well-defined and uniform sizes and nanomorphologies. The as-synthesized Au@MOF catalyst exhibited high catalytic activities in a wide variety of reactions under ambient conditions, such as the base-free aerobic oxidation of alcohols and oxidation/imine formation/reduction reaction sequences. Furthermore, the Au@MOF catalyst can be easily recovered and reused several times without leaching of metals or significant loss of activity.