Highly Efficient Au Nanocatalysts for Heterogeneous Continuous-Flow Reactions Using Hollow CeO₂ Microspheres as a Functional Skeleton

Hollow Au/CeO₂ as a highly efficient and stable heterogeneous catalyst is successfully used for a continuous-flow reaction. The hollow CeO₂ microspheres with thicknesses of 21 nm as functional supports can greatly improve the catalytic activity and stability of the Au nanoparticles. The catalytic activity of hollow Au/CeO₂ catalysts is 4.5 times higher than the Au catalysts without the hollow structure under the same reaction conditions for the reduction of 4-nitrophenol. Meanwhile, the hollow structure also accelerates the mass transfer of reactant for the continuous-flow system. A high turnover number of 65.7 mol h^–1 mol_Au^–1 is yielded for hollow Au/CeO₂ catalysts at a flow rate of 250 mL h^–1 with remarkable stability for a continuous-flow 4-nitrophenol reduction reaction. The present continuous-flow system exhibits a huge potential for the automation treatment of pollutant 4-nitrophenol