Cu behavior and catalytic properties on highly distributed CeO2-MgO supports: Impact of Cu loading in HTS reactions for waste-to-hydrogen production

Abstract

Achieving uniform dispersion of CeO₂-MgO supports presents a significant technical challenge due to their inability to form solid solutions. The crystallization of CeO₂ inhibits MgO structure formation, causing MgO to exist in an amorphous and unevenly distributed state within the CeO₂-MgO matrix. Consequently, many studies have focused on poorly dispersed CeO₂-MgO systems for catalyst development. This limitation not only prevents the full utilization of uniformly distributed CeO₂-MgO but also complicates the clear identification of interaction between active metal and support. In this study, a spray pyrolysis-assisted evaporation-induced self-assembly (EISA) method was employed to successfully synthesize uniformly dispersed CeO₂-MgO, and the behavior of Cu impregnated onto this well-dispersed support was investigated. Our findings revealed that the size and dispersion of Cu nanoparticles were strongly influenced by Cu loading, which significantly affected the redox properties of Cu while inducing simultaneous changes in the electronic structures of both Cu and Ce. These findings illustrate how thermally mobile Cu behaves on a uniformly distributed CeO₂-MgO support, emphasizing the importance of controlling active material behavior in catalyst design for high-temperature shift reactions. This provides key insights into optimizing catalytic performance and enhancing waste-to-hydrogen production by precisely controlling Cu distribution and its interaction with the support.