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

D´ALESSANDRO ORIANA; GARCIA PINTOS DELFINA; BEATRIZ IRIGOYEN; JUAN, ALFREDO; JORGE ENRIQUE SAMBETH

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 359 p. 14 - 20

0169-4332

Density functional theory calculations (DFT+U) were performed on a low dopingMn?Ce composite oxide prepared from experimental data, including X-ray diffraction(XRD) and temperature-programmed reduction (TPR). We considered a 12.5% Mn?doped CeO2 solid solution with fluorite?type structure, where Mn replaces Ce4+ leadingto an oxygen?deficient bulk structure. Then, we modeled the adsorption of phenol onthe bare Ce0.875Mn0.125O1.9375(111) surface. We also studied the effect of wateradsorption and dissociation on phenol adsorption on this surface, and compared thepredictions of DFT+U calculations with diffuse reflectance infrared Fourier transformspectroscopy (DRIFTS) measurements. The experimental results allowed us to bothbuild a realistic model of the low doping Mn?Ce composite oxide and support theprediction that phenol is adsorbed as a phenoxy group with a tilt angle of about 70°with respect to the surface.