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Dissociation of chlorobenzene (C6H5CI), Chlorothane (C2H5CI) and ispropyl chloride (C3H7CI) on ceria (CeO2) 111 surfaces

Miran, H.A., Altarawneh, M., Widjaja, H., Jaf, Z.N. and Jiang, Z-T (2016) Dissociation of chlorobenzene (C6H5CI), Chlorothane (C2H5CI) and ispropyl chloride (C3H7CI) on ceria (CeO2) 111 surfaces. In: Australian Institute of Physics (AIP) WA 2016 Postgraduate Conference, 13 October 2016, University of Western Australia, Perth.

Abstract

Chlorinated volatile organic compounds (Cl-VOCs) are toxic materials that are emitted from any fuel whenever a chlorine source is present. These compounds are often of environmentally persistent nature and induce toxic effects to the wildlife as well as to human health and the best way to control these harmful gases being by destructing them into smaller fragments. At first glance, these materials have been decomposed via thermal oxidation at temperature ~ 1000°C; in processes that are very energy intensive and may lead to the formation of the notorious dioxins compounds in post-combustion chambers. CeOz or CeOzbased materials as alternative of the expensive noble metals based material are widely used as catalysts in prominent industrial applications. Very recently, mounting experimental evidences have established robust catalytic behaviour of Ce02 toward dechlorinating and degradation of Cl-VOCs [ 1 ,2]. Among the various plausible terminations, Ce02(111) is the most stable surface involving mixed Ce/0 terminations. In this work, we inspected the dissociation of representative Cl-VOCs, namely chlorobenzene (C6H5Cl), chloroethane (CzH5Cl) and ispropyl chloride (C3H7Cl), termed as CB, CE and IC respectively, over the Ce02 (111) surface using density functional theory (DFT). The on-site Coulomb interaction correction (DFT +U) method developed by Dudarev et al [3] was employed to produce more accurate energetic profiles of these systems. Nudged Elastic Band (NEB) method [4] was used to calculate the reaction paths. The DFT calculations revealed that Ce02(111) surface mediates fission of the carbon-chlorine bonds in CB, CE and IC via accessible energy barriers of 3.32, 2.82 and 1.56 eV, respectively. The dissociated chlorine atoms and CxHy moieties exists in 1.64, 1.36 and 1.70 eV below the entrance channel for CB, CE and IC molecules, respectively. Results from this study should be helpful to understand the role of Ce02-based catalysts in destruction of persistent halogenated pollutants.

Publication Type: Conference Item
Conference Website: http://www.physics.uwa.edu.au/postgraduate-confere...
URI: http://researchrepository.murdoch.edu.au/id/eprint/34043
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