Nickel-Decorated Mesoporous Iron-Cerium Mixed Oxides: Microstructure and Catalytic Activity in Methanol Decomposition

Nickel-decorated mesoporous cerium-iron oxide composites were synthesized by a combination of incipient wetness impregnation and template-assisted hydrothermal techniques. The effects of the Fe/Ce ratio and the calcination temperature of cerium-iron oxides on the phase composition, texture, structure, and redox properties of the composites were studied by a combination of N₂ physisorption, XRD, high-resolution transmission electron microscopy, SEM, Mössbauer, Raman, XPS, ultraviolet-visible and FTIR spectroscopies, H₂-temperature-programmed reduction, and total oxidation of ethyl acetate as a catalytic test. The combined physicochemical characterization and in situ FTIR investigation of methanol decomposition was used for a proper understanding of the microstructure of the Ni/FeCe oxide composites and the mechanism of the reaction occurring on them. The complex role of the FeCe support in the stabilization of highly dispersed Ni particles, the generation of surface intermediates, and the impact of the support phase transformation under the reaction medium are discussed.