Facile preparation of triangular-like polycrystalline ceria as supporting carrier in catalysis exemplified by Ni/CeO2 catalyzed oxidation and hydrogenation reactions

Abstract

Ceria is a reducible oxide that has been extensively employed as supporting carrier in catalysis due to its unique redox and structural properties in combination with its strong interaction with the active phases. Recently, the synthesis of ceria nanostructures with uniform size and morphology has become a topic of extensive scientific interest in catalysis. Therefore, the combination of earth-abundant and cost-effective transition metals with fine-tuned ceria carriers could provide a platform for multifunctional materials in several energy and environmental applications. Herein, we originally explore the facile synthesis of ceria particles of triangular-like morphology with improved textural and structural characteristics and their subsequent application as supporting carrier of nickel active phase. The as-prepared Ni/CeO₂ catalysts were thoroughly characterized and catalytically assessed for both oxidation (CO oxidation) and reduction (CO₂ hydrogenation) processes to demonstrate the effectiveness of ceria triangular structures as supporting materials in catalysis. The results clearly revealed the pivotal role of ceria nanostructure on the physicochemical properties and in turn on the catalytic performance of the nickel-ceria binary system. The improved reducibility and oxygen kinetics of ceria carrier, along with its abundance in structural defects and Ce³⁺ species, could be considered as the dominant factors towards determining the catalytic performance, offering highly active and selective ceria-based transition metal catalysts.