Domain-Confined Multiple Collision Enhanced Catalytic Soot Combustion over a Fe2O3/TiO2-Nanotube Array Catalyst Prepared by Light-Assisted Cyclic Magnetic Adsorption

The ordered TiO2 nanotube array (NA)-supported ferric oxide nanoparticles with adjustable content and controllable particulate size were prepared through a facile light-assisted cyclic magnetic adsorption (LCMA) method. Multiple techniques such as SEM, TEM, EDX, XRD, EXAFS, XPS, UV-vis absorption, and TG were employed to study the structure and properties of the catalysts. The influencing factors upon soot combustion including the annealing temperature and loading of the active component in Fe2O3/TiO2-NA were also investigated. An obvious confinement effect on the catalytic combustion of soot was observed for the ferric oxide nanoparticles anchored inside TiO2 nanotubes. On the basis of the catalytic performance and characterization results, a novel domain-confined multiple collision enhanced soot combustion mechanism was proposed to account for the observed confinement effect. The design strategy for such nanotube array catalysts with domain-confined macroporous structure is meaningful and could be well-referenced for the development of other advanced soot combustion catalysts.