Nanoengineering 2D ceria-perovskite monolayers on SrTiO3 nanocubes: structure-redox property relationship

Abstract

Achieving the full potential of ceria-based catalysts relies on maximizing the utilization of the Ce⁴⁺/Ce³⁺ redox couple. This study presents a strategy to synthesize highly efficient catalysts by epitaxially dispersing cerium oxide onto strontium titanate (SrTiO₃) nanocubes. Leveraging the structural compatibility between the fluorite (CeO₂) and perovskite (SrTiO₃) structures, revealed by atomic resolution scanning transmission electron microscopy, reductive thermal treatments are used to generate two-dimensional (2D) ceria-perovskite nano-overlayers—precisely one unit-cell thick—that uniformly cover the SrTiO₃ support. This atomic-scale control results in a catalyst system that achieves 100% cerium redox utilization, exhibiting significantly enhanced reducibility and a stabilized surface compared to bulk ceria. The experimental evidences are corroborated by density functional theory calculations. This work establishes a robust foundation for designing lanthanide-lean catalysts with superior chemical properties by exploring analogous fluorite-perovskite support interfaces.