A DFT study of phenol adsorption on a low doping Mn–Ce composite oxide model

Density functional theory calculations (DFT+U) were performed on a low doping Mn–Ce composite oxide prepared from experimental data, including X-ray diffraction (XRD) and temperature-programmed reduction (TPR). We considered a 12.5% Mn–doped CeO<sub>2</sub> solid solution with fluorite–t...

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Detalles Bibliográficos
Autores principales: D'Alessandro, Oriana, García Pintos, Delfina, Juan, Alfredo, Irigoyen, Beatriz, Sambeth, Jorge Enrique
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2015
Materias:
DFT
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/103101
https://www.sciencedirect.com/science/article/abs/pii/S0169433215023971
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Sumario:Density functional theory calculations (DFT+U) were performed on a low doping Mn–Ce composite oxide prepared from experimental data, including X-ray diffraction (XRD) and temperature-programmed reduction (TPR). We considered a 12.5% Mn–doped CeO<sub>2</sub> solid solution with fluorite–type structure, where Mn replaces Ce<sup>4+</sup> leading to an oxygen–deficient bulk structure. Then, we modeled the adsorption of phenol on the bare Ce<sub>0.875</sub>Mn<sub>0.125</sub>O<sub>1.9375</sub>(111) surface. We also studied the effect of water adsorption and dissociation on phenol adsorption on this surface, and compared the predictions of DFT+U calculations with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) measurements. The experimental results allowed us to both build a realistic model of the low doping Mn–Ce composite oxide and support the prediction that phenol is adsorbed as a phenoxy group with a tilt angle of about 70° with respect to the surface.