A Study of How LaFeO<sub>3</sub> and CaTiO<sub>3</sub> Supports Affect the Oxidation, Hydrogenation, and Methane Steam Reforming Activity of Pt and Ni Catalysts
Siwon Lee, Matteo Monai, Kai Shen, Jian Chang, John M. Vohs, Raymond J. Gorte
Abstract
The structure and catalytic properties of Pt and Ni supported on thin films of LaFeO3 and CaTiO3, prepared by atomic layer deposition (ALD), were investigated. X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) show that reduction at 1073 K causes Pt–Fe intermetallic compound formation for Pt/LaFeO3. For Pt/CaTiO3, 1073 K reduction induces local decomposition of the CaTiO3 with migration of Ti to the Pt. Reduced Pt/LaFeO3 and Pt/CaTiO3 exhibited CO oxidation activity similar to that for Pt supported on MgAl2O4 but were much less active for propane oxidation and hydrogenation of 1-hexene and toluene. In contrast, Ni/CaTiO3 behaved similarly to a conventional supported Ni catalyst for the methane steam reforming (MSR) and 1-hexene hydrogenation. There was also no evidence for local decomposition of the perovskite in the vicinity of the Ni particles. The results obtained in this study demonstrate that metal–perovskite interactions that affect reactivity are specific to each component.