Pt/Al2O3La2O3 catalysts stable at high temperature in air, prepared using a "one-pot" sol-gel process: Synthesis, characterization, and catalytic activity in the partial oxidation of CH4

Author(s)

Rocha, Kleper de O. ; Macedo, Wagner C. ; Marques, Clelia M. P. ; Bueno, Jose M. C.

• Document type: Journal article
• Source: Chemical Engineering Science; v. 229, p. 12-pg., 2021-01-16.

Abstract

Pt/Al2O3La2O3 catalysts were prepared by a "one-pot" sol-gel method, with different final synthesis tem-peratures. The catalysts were characterized by in situ X-ray absorption spectroscopy (XAS). The partial oxidation of methane (POM) reaction was used to evaluate catalyst stability. DRIFTS-CO analysis indicated the interaction of Pt with the support by Pt-O-(Al-O, La-O) bonds, which suppressed bridge CO adsorption. In situ POM-DXAS-MS analysis showed that after use in the POM reaction at about 1000 K and cooling to room temperature, the Pt/Al2O3La2O3 catalysts presented partial oxidation of Pt-0, indicating the formation of a core-shell structure. The nanoparticles generated using the "one-pot" method showed higher Pt-O-Al type interaction with the support, relative to free Pt-O at the surface, resulting in high resistance to sintering in the POM reaction. The temperature used in the "one-pot" synthesis significantly influenced the Pt-O-Al interaction, which modified the resistance to sintering at 1073 K in air. (c) 2020 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 18/01258-5 - Novel chemical catalytic and photocatalytic processes for the direct conversion of methane and CO2 to products
• Grantee: José Maria Correa Bueno
• Support Opportunities: Research Projects - Thematic Grants