Use of X-Ray Photoelectron Spectroscopy as an analytical tool for the study of contamination by Teflon in the synthesis of Mo(VI)Cl2O2Bipy/TiO2 catalysts

• Published in: Revista colombiana de química Vol. 51; no. 2
• Main Authors: Amaya Vesga, Álvaro Andrés, Martínez Quiñónez, Henry, Gómez Tarazona, Raúl Armando, Mendoza Castellanos, Yeisson Ricardo, Martínez Ortega, Fernando
• Format: Journal Article
• Language: English
• Published: Bogota Universidad Nacional de Colombia 13.04.2023
• Subjects: Catalysts; Contamination; Dehydration; Fluorine; High temperature; Molecular chains; Photoelectrons; Polytetrafluoroethylene; Solvents; Spectroscopic analysis; Spectrum analysis; Titanium dioxide; X ray photoelectron spectroscopy
• ISSN: 0120-2804; 2357-3791
• DOI: 10.15446/rev.colomb.quim.v51n2.101969

The preparation of catalysts can involve various sources of contamination, which can seriously affect the quality of the prepared materials. In the present work, a case of fluorine contamination in a set of catalyst samples was studied, in which using the X-Ray Photoelectron Spectroscopy (XPS) technique, it was evidenced by the F 1s signal that this element was present in the form of Teflon, since its binding energy corresponded mainly to the CF2 species. Furthermore, using the C 1s signal, it was also possible to corroborate the presence of the CF2 group, which is associated with the main component of the Teflon carbon chains. The use of this information made it possible to identify that the solvent dehydration procedure (previous step to obtaining the catalysts) could lead to contamination with Teflon since it involved various accessories with Teflon, organic solvents and high temperature; the Teflon tape and the magnetic stirrer being the possible sources of contamination.