Enhanced Oxygen Vacancies in Ce-Doped SnO2 Nanofibers for Highly Efficient Soot Catalytic Combustion

Abstract

In this paper, cerium was incorporated into polyhydroxyltriacetictin (PHTES) using the sol-gel method combined with electrospinning technology to prepare a series of composite oxide fiber catalysts SnxCe1−xO2 in different proportions. The structures and soot catalytic activities of SnxCe1−xO2 fibers were studied under loose contact conditions. When Ce entered the crystal lattice of SnO2, the structural symmetry of the SnO2 was destroyed, which inhibited the crystallization and grain growth of the fiber, and fiber catalysts with a larger specific surface area were obtained. Moreover, the introduction of Ce improved the number of oxygen vacancies and redox ability of the catalyst, thus promoting the catalytic activity of the catalyst for soot particles. In particular, among them, the Sn0.7Ce0.3O2 fiber catalysts had the strongest catalytic oxidation ability regarding soot particles and could oxidize soot particles at a lower temperature and faster catalytic rate. The results of the temperature-programmed oxidation of Sn0.7Ce0.3O2 fiber catalyst, conducted three times under the same conditions, were basically consistent, indicating that the experimental results are reliable and repeatable. In addition, the Sn0.7Ce0.3O2 fiber catalyst showed good cycle stability.