INTEC   05402
INSTITUTO DE DESARROLLO TECNOLOGICO PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Insights into the mechanism for oxidation of volatile organic compounds on ceria based catalysts
Autor/es:
CALAZA, FLORENCIA C.; COLLINS, SEBASTIAN E.; MARIELA BRITES HELU
Lugar:
Orlando
Reunión:
Conferencia; 257th ACS National Meeting; 2019
Institución organizadora:
AMERICAN CHEMICAL SOCIETY
Resumen:
It is well known that VOCs being recognized as major responsible for the increase in global air pollution. Catalytic combustion is an efficient technology for the abatement of VOC, which are oxidized over a catalyst at temperatures much lower than those of the thermal process. Specifically, gold supported catalysts on CeO2 have shown a great performance in the oxidation of CO, MeOH, toluene, etc. However their deactivation is quite fast due to the fact that NPs sinter even at low temperature. One of the most used strategies to overcome this drawback is to use bimetallic NPs where the second metal stabilizes Au and increases the catalytic activity. In this sense, the aim of this project is to study the performance in toluene oxidation of Au-Pd and Au-Cu/CeO2 catalysts whose promising activity has been proved in other oxidation reactions. Besides, it is important to clarify the role of the support in such reaction. Ceria has the key property of high oxygen storage capacity which originates in its ability to rapidly switch from Ce3+ to Ce4+ oxidation states as the environment changes from reducing to oxidizing and vice versa. Its redox behaviour is influenced by the substituent lattice groups that could be incorporated during different catalyst pretreatments and could affect the oxidation of VOC. This could be understood as the influence of oxygen vacancies and/or absorbed or coadsorbed H on the activation of oxygen molecules. The latter leads to the formation of superoxide and peroxide molecules on the surface, which could in principle be highly reactive towards oxidation of organic molecules.In the present, will be shown results from IR spectroscopy and mass spectrometry for the interaction of O2 with modified CeO2 based material, by creating vacancies following different reduction treatments. The possible role of the vacancies and/or presence of H atoms in the electron transfer from the surface to the oxygen molecule will be discussed.