Speaker
Description
The environmental impact caused by man has reached levels of no return. Among the problems of this nature are climate change and air pollution. The use of materials to remove contaminants has been widely studied. However, the search for new materials that improve efficiency in contaminant removal has been constant. In this sense, gold is known for its ability to improve various material properties. It facilitates the conditions to catalyze several reactions of high interest in environmental remediation. It is well known that gold behaves as a cation in a wide variety of materials of which it is a part or in which it is deposited or incorporated. However, the existence of anionic gold in some compounds has also been reported in the literature. Although it has been discussed in terms of experimental evidence, and it is known that it can exist in double perovskite-type structures, so far, there is no atomic-scale explanation of the interaction mechanisms, as well as the conditions that lead to the anionic behavior of gold in this type of structures and the potential applications it has in environmental remediation. Prominent candidates for finding anionic gold with great possibilities for application in environmental remediation are rare earth oxides since they have been shown as excellent catalysts for the CO oxidation reaction with great selectivity, in addition to the low electronegativity that f-block metals have. In this work, the modification of CeO2 with Au was simulated employing density functional theory (DFT) calculations. Surface models of (111) and (100) were constructed. The most probable adsorption sites were determined by electrostatic potential maps. Au adsorption was assessed by constructing several models. Determination of anionic gold behavior was carried out by Bader charge analysis.
This work was supported by
We thank DGAPA-UNAM projects IG101124 and IA100624 for partial financial support. Calculations were performed in the DGCTIC-UNAM Supercomputing Center projects LANCAD-UNAM-DGTIC-368 and LANCAD-UNAM-DGTIC-422. JGS acknowledges LNS-BUAP project 202201042N and THUBAT KAAL IPICYT supercomputing center project TKII-JGSA001 for their computational resources.
Reference
T.A. Zepeda, R. Ponce-Pérez, A. Solis-Garcia, J. Guerrero-Sanchez, S. Fuentes, S.A. Gomez, Boosting oxygen activation in ceria-oxide via gallium addition, Appl Catal B 336 (2023). https://doi.org/10.1016/j.apcatb.2023.122936.
| Keywords | anionic gold, rare earth oxides, CeO2, DFT |
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| Author approval | I confirm |
| Author will attend | I confirm |