Hollow zeolite-encapsulated Fe-Cu bimetallic catalysts for phenol degradation

Highly dispersed Fe-Cu bimetallic oxide nanoparticles were successfully encapsulated in hollow Silicalite-1 single crystals (Fe2O3[email protected] S-1) by tetrapropylammonium hydroxide (TPAOH) hydrothermal treatment with an “impregnation-dissolution-recrystallization” process. Due to the Fe-Cu bimetallic interaction compared with single iron oxide, Fe-Cu bimetallic oxide exhibits a higher dispersion with the particle size decreasing from ∼11.3 nm to ∼3.7 nm. For aqueous phenol degradation, the Fe2O3[email protected] S-1 catalyst exhibits high activity attributed to the enhanced transport of reactants/products in the short microporous channels (20 nm) and the small metal oxide particle size. Interestingly, the particle size of encapsulated Fe2O3CuO (3.7 nm) is larger than that of zeolite micropore (0.53 nm), which helps preventing the leaching of metal oxide that is a significant problem for conventional supported Fe catalyst in this reaction.