Hollow Zeolites Encapsulating Ultra-Low Noble Metal Nanoparticles for HMF Oxidation

We report the development of zeolite nanocapsules (MCM-22 and ZSM-5) encapsulating ultra-low amount (0.01 wt%) of noble metal nanoparticles (Gold, Platinum and Palladium) for the oxidation of HMF. These catalysts showed enhanced HMF conversion (> 95%) with higher yield (> 90%) of FDCA under mild conditions (60 °C, 0.3 MPa oxygen) in an organic solvent-free medium in 6 h. We also investigated the effect of size and amount of gold nanoparticles encapsulated inside zeolite capsules for the oxidation of HMF. We found that Au cluster loaded MCM-22 showed enhanced HMF conversion and yield of FDCA (91%).