4-8 July 2016
Kramer Law building
Africa/Johannesburg timezone
Paper Review: Initial screening in progress
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The SCC-DFTB study of H2O interaction with TiO2 supported Pd catalyst

Presented by Ms. Moyahabo Hellen CHUMA on 5 Jul 2016 from 15:20 to 15:40
Type: Oral Presentation
Track: Track A - Division for Physics of Condensed Matter and Materials

Abstract

The supported metal nanoparticles are of great importance in many industrial catalytic processes, such as oxidation of methane, carbon monoxide and formic acid. In particular, the platinum group metals (PGM) such as Pd, Pt and Rh supported on metal oxides are being considered. Palladium is often used as a catalyst for many processes in emissions control technologies. This is due to its potential of becoming a novel catalyst for low temperature methane combustion. During the methane oxidation, H<sub>2</sub>O is produced and it is important to understand the behaviour of this molecule as it gets in contact with catalyst. The interaction of H<sub>2</sub>O molecules with Pd nanoclusters and TiO<sub>2</sub> supported Pd nanoclusters were investigated using the self-consistent-charge density functional tight binding (SCC-DFTB) approach as implemented within the DFTB+ code [5]. Firstly, the interaction of H<sub>2</sub>O molecule with Pd<sub>13</sub> nanocluster was investigated. The results show that when H<sub>2</sub>O interact with Pd nanoclusters, it dissociate into OH and H forming a Pd – O bond length of 1.992 Å and Pd – H bond length of 1.571 Å, respectively. Secondly, the interaction H<sub>2</sub>O with TiO<sub>2</sub>(101) supported Pd<sub>13</sub> on various adsorption sites preferred the bridge adsorption site, however no dissociation was observed. This gave an average bond length of 1.979 Å with adsorption energy of -1.887 eV. Lastly, molecular dynamics (MD) calculations were performed on the most preferred orientation of H<sub>2</sub>O adsorbed on TiO<sub>2</sub>(101) supported Pd<sub>13</sub> system. It was obtained that the H<sub>2</sub>O molecule dissociates into OH and H at about 598 K.

Award

yes

Level

PhD

Supervisor

PE Ngoepe Phuti.Ngoepe@ul.ac.za University of Limpopo

Paper

No

Permission

No

Place

Location: Kramer Law building
Address: UCT Middle Campus Cape Town
Room: LT1


Primary authors

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