Name: Supplementary material from "Cation-doping strategies for tuning of zirconia acid–base properties"
Description: The role of Y-, Ca- and Ce-doping of cubic zirconia (c-ZrO<sub>2</sub>) (111) surface on its acidity, basicity and the interplay between surface acid–base pairs is investigated by computational methods. The most stable surface structures for this investigation were initially determined based on previous studies of Y-doped c-ZrO<sub>2</sub> (111) and by a detailed exploration of the most stable configuration for Ca-doped c-ZrO<sub>2</sub> (111) and Ce-doped c-ZrO<sub>2</sub> (111). Next, surface mapping by basic probe molecules (NH<sub>3</sub> and pyridine) revealed a general reduction of the acidity of the surface sites, although a few exceptions were observed for zirconium ions at NNN positions to the oxygen vacancy and at an NN position to the dopant. Similarly, CO<sub>2</sub> adsorption over basic sites revealed a cooperative interplay between acid–base groups. In this case, however, the overall effect observed was the decrease of the calculated adsorption energies when compared to the pristine surface. Moreover, spontaneous formation of <i>η</i><sup>3</sup>-CO<sub>2</sub> systems from initial <i>η</i><sup>2</sup>-CO<sub>2</sub> configurations indicates a decrease in the required energy for forming oxygen vacancies in the doped ZrO<sub>2</sub> systems at NNN positions or further away from the existing vacancy site.Keywords: acid–base properties, biofuels, zirconia, deoxygenation reactions, biofuel upgrading
DOI: 10.6084/m9.figshare.c.5839296
Resository: https://figshare.com
Start date: 2022-02-12 00:00:00 UTC
End date:
Related Article: Cation-doping strategies for tuning of zirconia acid–base properties
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