Unveiling the structural behavior of bimetallic AuCu/TiO2 catalysts in the CO oxidation: A combined in-situ spectroscopic and theoretical study
Por:
Araiza D.G., Celaya C.A., Solís-Casados D.A., Muñiz J., Zanella R.
Publicada:
1 ene 2024
Ahead of Print:
1 jun 2024
Resumen:
Bimetallic AuCu/TiO2 catalysts were thoroughly studied during the CO oxidation reaction via three in-situ spectroscopic techniques (FTIR, UV–Vis and Raman) and density functional theory (DFT) calculations. Samples were synthesized through the deposition–precipitation with urea (DPU) method, and ex-situ characterized by several techniques. The superior catalytic activity displayed by the AuCu/TiO2 sample was associated with the presence of nanoparticles in the form of heterodimers composed of the Au and CuXO phases in close interaction with the TiO2 support. In-situ DRIFTS results indicated that gold nanoparticles (NPs) presented some restructuration in the monometallic sample, while this event did not occur in the bimetallic one. The better stability on the AuCu/TiO2 catalyst was related to the partial migration of CuXO species to the surface of the NPs, also confirmed through in-situ UV–Vis spectroscopy. The favorable role played by the TiO2 reducibility was established through in-situ Raman spectroscopy. Moreover, findings obtained by DFT confirmed the experimentally evidenced structural modifications. © 2024
Filiaciones:
Araiza D.G.:
Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Ciudad de México, C.P. 04510, Mexico
Celaya C.A.:
Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Km 107 Carretera Tijuana-Ensenada, B.C., C.P, Ensenada, 22800, Mexico
Solís-Casados D.A.:
Centro Conjunto de Investigación en Química Sustentable, UAEM-UNAM, Carretera Toluca-Atlacomulco Km 14.5, Unidad San Cayetano, Estado de México, Toluca, C.P. 50200, Mexico
Muñiz J.:
Instituto de Energías Renovables, Universidad Nacional Autónoma de México, Priv. Xochicalco s/n, Col. Centro, Morelos, Temixco, C.P. 62580, Mexico
Zanella R.:
Instituto de Ciencias Aplicadas y Tecnología, Universidad Nacional Autónoma de México, Ciudad de México, C.P. 04510, Mexico
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