Synergistic effect and mechanism of mass transfer and catalytic oxidation of octane degradation in yolk-shell Fe3O4@C/Fenton system

Volatile organic compound (VOC) emissions are a global environmental concern because of their potential health risks. The removal of refractory VOCs calls for advanced technologies with powerful oxidative ability and high mass transfer efficiency. In this study, a yolk-shell Fe 3 O 4 @C/Fenton system was designed to improve octane removal efficiency. The octane removal efficiency at equilibrium was increased by 24.7% relative to that of the Fe 3 O 4 /Fenton system, and the main intermediate or byproduct levels decreased by 89.4%. The yolk-shell Fe 3 O 4 @C displayed higher catalytic and mass transfer efficiencies for octane degradation than Fe 3 O 4 . A synergistic effect of mass transfer enhancement and catalytic oxidation was observed in the yolk-shell Fe 3 O 4 @C/Fenton system. The mechanism of the synergistic effect of mass transfer and octane degradation, a regional reaction theory for the yolk-shell structure, and octane removal pathways were proposed and supported by the octane removal results and byproducts detection and measurement. This yolk-shell Fe 3 O 4 @C/Fenton system provides an effective and advanced way to treat refractory and hydrophobic VOCs, and its preparation can be extended to other high-efficiency core-shell structure catalyst-carbon materials.