Reduction of (100)-Faceted CeO₂ for Effective Pt Loading

Although the function and stability of catalysts are known to significantly depend on their dispersion state and support interactions, the mechanism of catalyst loading has not yet been elucidated. To address this gap in knowledge, this study elucidates the mechanism of Pt loading based on a detailed investigation of the interaction between Pt species and localized polarons (Ce³⁺) associated with oxygen vacancies on CeO₂(100) facets. Furthermore, an effective Pt loading method was proposed for achieving high catalytic activity while maintaining the stability. Enhanced dispersibility and stability of Pt were achieved by controlling the ionic interactions between dissolved Pt species and CeO₂ surface charges via pH adjustment and reduction pretreatment of the CeO₂ support surface. This process resulted in strong interactions between Pt and the CeO₂ support. Consequently, the oxygen-carrier performance was improved for CH₄ chemical looping reforming reactions. This simple interaction-based loading process enhanced the catalytic performance, allowing the efficient use of noble metals with high performance and small loading amounts.