Banca de DEFESA: TIAGO MENDES DE SOUZA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : TIAGO MENDES DE SOUZA
DATE: 31/12/2021
TIME: 09:00
LOCAL: campus 6
TITLE:
Water Adsorption Study in Silicon-Aluminum Nanoclusters.
KEY WORDS:
clusters; aluminium; silicon; adsorption; hydrogen formation
PAGES: 68
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química Teórica
SUMMARY:
Given the necessity for new catalysts for the production of hydrogen gas from the water splitting reaction (an alternative to fossil fuels), the interactions between aluminum and silicon nanoclusters with water have been studied in this work. These two elements already have applications in electronics and Al has known catalytic activity. When these two are mixed in the atomic scale, their properties become different from pure elements. For this reason, water adsorption (one of the main existing hydrogen sources) to the Al8, Si8, Al4Si4, Al2Si6, Al13, Si13, Al12Si e Al2Si11 nanoclusters has been investigated. Calculations at the MP2 level were performed with the GAMESS computational package using cc-pVDZ basis set for obtain the energies and vibrational frequencies.
Of the clusters evaluated, the alloys formed by both aluminum and silicon had higher adsorption energies than those of pure clusters. The best results were obtained for clusters of eight atoms, with three of the four structures evaluated presenting energies above 0,500eV. The only thirteen atoms cluster that presented energy in this range was Al2Si11. It has also been noticed that the adsorption was more effective in alloys with low aluminum contented, and the two highest adsorption energies were 0,648eV and 0,610eV, corresponding to the Al2Si11 and Al2Si6 clusters respectively. It has been shown that the interaction of water with pure silicon clusters is weak, with adsorption energies below 0,400eV. At simulated infra red spectrum, it is possible to notice the increase in intensity and the red shift of the peaks due to the interaction with water, a particularly pronounced effect for clusters with higher adsorption energies.
BANKING MEMBERS:
Interno - EUDES LORENCON
Externo à Instituição - MAICON PIERRE LOURENÇO - UFES
Externo à Instituição - LUÍS PEDRO VIEGAS