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

Abstract

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