Catalytic Oxidation of n-Decane, n-Hexane, and Propane over Pt/CeO₂ Catalysts.

ABSTRACT: Pt species with different chemical states and structures were supported on CeO₂ by solution reduction (Pt/CeO₂-SR) and wet impregnation (Pt/CeO₂-WI) and investigated in catalytic oxidation of n-decane (C₁₀H₂₂), n-hexane (C₆H₁₄), and propane (C₃H₈). Characterization by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, H₂-temperature programming reduction, and oxygen temperature-programmed desorption showed that Pt⁰ and Pt²⁺ existed on Pt nanoparticles of the Pt/CeO₂-SR sample, which promoted redox, oxygen adsorption, and activation. On Pt/CeO₂-WI, Pt species were highly dispersed on CeO₂ as the Pt-O-Ce structure, in which surface oxygen decreased significantly. The Pt/CeO₂-SR catalyst presents high activity in oxidation of C₁₀H₂₂ with a rate of 0.164 μmol min^-1 m^-2 at 150 °C. The rate increased with oxygen concentration. Moreover, Pt/CeO₂-SR presents high stability on feed stream containing 1000 ppm C₁₀H₂₂ at gas hour space velocity = 30,000 h^-1 as low as 150 °C for 1800 min. The low activity and stability of Pt/CeO₂-WI were probably related to its low availability of surface oxygen. In situ Fourier transform infrared results showed that the adsorption of alkane occurred through the interaction with Ce-OH. The adsorption of C₆H₁₄ and C₃H₈ was much weaker than that of C₁₀H₂₂, which resulted in the decrease in activity for C₆H₁₄ and C₃H₈ oxidation of Pt/CeO₂ catalysts.

SUBMITTER: Gao X 

PROVIDER: S-EPMC9948155 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature