Entropy Engineering Enables Perovskite-Derived Ni-Co-Cu/La₂O₃-Oᐧ_V Catalyst for Efficient and Stable CO₂-to-CO Conversion

Abstract

The challenge in designing efficient reverse water-gas shift (RWGS) catalysts necessitates high CO selectivity and CO₂ conversion while suppressing CH₄ formation and ensuring thermal stability. This study proposes a multi-principal entropy engineering to successfully synthesize a medium-entropy perovskite oxide catalyst, La₄NiCoAlCuO₃ (MEO). Entropy-driven delayed diffusion facilitated Ni-Co-Cu alloy phase formation during reduction, while the simultaneously formed La₂O₃ support established a strong metal-support interaction (SMSI). This SMSI, combined with the physical confinement effect of the hierarchical porosity structure, effectively stabilized the Ni/Co/Cu nanoparticles against high-temperature agglomeration. Entropy-induced lattice distortion generated abundant oxygen vacancies, providing strong adsorption sites for CO₂ and promoting H₂ dissociation into active H* species. These synergistic effects created a tripartite active configuration ("alloy-oxide interface-oxygen vacancies") within MEO, enabling an "efficient adsorption-activation-conversion" pathway. Consequently, MEO achieved outstanding catalytic performance and high thermal stability at 550°C, maintaining ≥95% CO selectivity over 1,000 hours. In contrast, an enthalpy-dominated La₅NiCoAlCuZrO₃ (Zr-MEO) suffered from significantly reduced activity due to multiphase segregation and oxygen vacancy scarcity. This work elucidates entropy engineering's pivotal role in stabilizing catalyst structure and modulating interfacial activity, proposing an "entropy-driven structural engineering" strategy for designing durable, highly active, and selective high-temperature CO₂ hydrogenation catalysts.

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