https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) from oxidation of 4,4'-dichlorobiphenyl (4,4'-DCB) https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42740  600°C) lead to selective formation of a small number of lower-chlorinated pollutants, whereas reactive surfaces, as evident from literature, engender catalytic (but non-selective) appearance of a large number of higher-chlorinated and toxic chloroaryl congeners, even at temperature of less than 300°C. Results from the density functional theory (DFT) calculations indicate that, majority of the detected congeners of PCDF arise from the oxidative transformation of the parent 4,4′-DCB; i.e., not from the commonly suggested precursors of chlorinated phenols and benzenes. Our findings have significant importance to understanding the emission of PCB and PCDD/F in combustion processes.]]> Wed 24 May 2023 15:48:24 AEST ]]> Formation of chlorobenzenes by oxidative thermal decomposition of 1,3-dichloropropene https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27704 Wed 24 Jul 2019 15:36:26 AEST ]]> Oxidation of 4-bromo-4'-chlorobiphenyl, model species for forming mixed halogenated aromatic compounds https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33723 ortho substituted PXB as a model species yields a large number of halogenat ed compounds, including monochloro- and monobromobenzene and higher halogenated benzenes and naphthalenes and derivatives of halogenated benzenes (such as 1-chloro-4-ethynylbenzene). We also detect small amounts of chlorinated and mixed halogenated dibenzofurans. The present study provides insights into the formation of several classes of halogenated and mixed-halogenated pollutants in combustion processes involving both bromine and chlorine sources, such as those of brominated flame retardants and PVC plastics.]]> Wed 12 Dec 2018 15:55:08 AEDT ]]> A first-principles density functional study of chlorophenol adsorption on Cu₂O(110):CuO https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:7987 Wed 11 Apr 2018 10:05:26 AEST ]]> Electronic structure of the CuCl₂ (100) surface: a DFT first-principle study https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20877 Tue 16 Oct 2018 12:09:00 AEDT ]]> Probing the chemical reactivity of the B<inf>2</inf>O<inf>3</inf> -I (1 0 1) Surface: Interaction with H<inf>2</inf>O and H<inf>2</inf>S https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:51853 Thu 21 Sep 2023 09:40:56 AEST ]]> Adsorption of 2-chlorophenol on Cu₂O(1 1 1)–CuCUS: a first-principles density functional study https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9350 Sat 24 Mar 2018 08:36:28 AEDT ]]> Theoretical study of reactions of HO₂ in low-temperature oxidation of benzene https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9349 Sat 24 Mar 2018 08:36:28 AEDT ]]> A DFT study on the self-coupling reactions of the three isomeric semiquinone radicals https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9345 Sat 24 Mar 2018 08:36:27 AEDT ]]> Mechanisms for formation, chlorination, dechlorination and destruction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:8041 Sat 24 Mar 2018 08:35:04 AEDT ]]> Pyrolysis of permethrin and formation of precursors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) under non-oxidative conditions https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:8082 Sat 24 Mar 2018 08:34:28 AEDT ]]> Quantum chemical study of low temperature oxidation mechanism of dibenzofuran https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:996 Sat 24 Mar 2018 08:29:49 AEDT ]]> Theoretical study of the ammonia-hypochlorous acid reaction mechanism https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:10414 Sat 24 Mar 2018 08:12:38 AEDT ]]> Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in oxidation of captan pesticide https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:12273 Sat 24 Mar 2018 08:10:12 AEDT ]]> Theoretical study of unimolecular decomposition of catechol https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9906 Sat 24 Mar 2018 08:07:40 AEDT ]]> Theoretical study on the thermodynamic properties and self-decomposition of methylbenzenediol isomers https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9905 Sat 24 Mar 2018 08:07:40 AEDT ]]> Thermochemical properties and decomposition pathways of three isomeric semiquinone radicals https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:9907 Sat 24 Mar 2018 08:07:40 AEDT ]]> Dehydrohalogenation of ethyl halides https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19259 Sat 24 Mar 2018 08:06:33 AEDT ]]> Theoretical study on the unimolecular decomposition of proline https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19097 Sat 24 Mar 2018 08:05:15 AEDT ]]> Rate constants for hydrogen abstraction reactions by the hydroperoxyl radical from methanol, ethenol, acetaldehyde, toluene, and phenol https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17541 2). In this study, we calculate energy profiles for the sequence: reactant + HO₂ → [complex of reactants] → transition state → [complex of products] → product + H₂O₂ for methanol, ethenol (i.e., C₂H₃OH), acetaldehyde, toluene, and phenol. Rate constants are provided in the simple Arrhenius form. Reasonable agreement was obtained with the limited literature data available for acetaldehyde and toluene. Addition of HO₂ to the various distinct sites in phenol is investigated. Direct abstraction of the hydroxyl H was found to dominate over HO₂ addition to the ring. The results presented herein should be useful in modeling the lower temperature oxidation of the five compounds considered, especially at low temperature where the HO₂ is expected to exist at reactive levels.]]> Sat 24 Mar 2018 08:03:57 AEDT ]]> A mechanistic and kinetic study on the formation of PBDD/Fs from PBDEs https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20091 Sat 24 Mar 2018 08:00:08 AEDT ]]> Quantum chemical study on formation of PCDT/TA from 2-chlorothiophenol precursor https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20094 Sat 24 Mar 2018 08:00:07 AEDT ]]> Theoretical study on thermochemical parameters and IR spectra of chlorinated isomers of nitrobenzene https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:18371 Sat 24 Mar 2018 07:52:38 AEDT ]]> Theoretical study on thermochemical parameters and pKa values for fluorinated isomers of toluene https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20155 Sat 24 Mar 2018 07:51:37 AEDT ]]> Formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) by precursor pathways in oxidation of pesticide alpha-cypermethrin https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20190 Sat 24 Mar 2018 07:51:32 AEDT ]]> Adsorption of chlorophenol on the Cu(111) surface: a first-principles density functional theory study https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:5163 Sat 24 Mar 2018 07:49:41 AEDT ]]> 2-chlorophenol adsorption on Cu(100): first-principles density functional study https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:5224 Sat 24 Mar 2018 07:44:20 AEDT ]]> Density functional theory periodic slab calculations of adsorption and dissociation of H2O on the Cu2O(110):CuO surface https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28811 2O has many prominent industrial and environmental applications. This study represents detailed density-functional theory calculations investigating the adsorption of a water molecule on a Cu₂O(110):CuO surface; one of the two most stable Cu₂O surfaces under practical catalytic conditions of temperatures and pressures. We report herein structural geometries and binding energies for all plausible molecular and dissociative interaction of HO with the surface. The water molecule is found to interact weakly with the Cu₂O(110):CuO surface, forming several vertical and flat orientations where the latter was found to offer the most preferred site with a binding energy at 0.389 eV. Dissociation of a water molecule on this surface is found to incur a modest endothermcity of 0.71 eV. PACS Nos.: 73.22.−f, 61.46.Df, 61.46.−w.]]> Sat 24 Mar 2018 07:38:25 AEDT ]]> S-nitrosation of aminothiones https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27420 eq corresponds to 559-382 M(⁻²) for thioacetamide (TA, 15-25 °C) and 12600-5590 M(⁻²) for thiourea (TU, 15-35 °C), whereas the reaction enthalpies amount to -27.10 ± 0.05 kJ for TA and -29.30 ± 0.05 kJ for TU. Theoretical calculations via a thermochemical cycle agree well with reaction free energies from experiments, with errors of -2-4 kJ using solvation method SMD in conjunction with hybrid meta exchange-correlation functional M05-2X and high-accuracy multistep method CBS-QB3 for gas-phase calculations. The kinetic rates increase with acidity at activation energies of 54.9 (TA) and 66.1 kJ·mol(-1) (TU) for the same temperature range, confirming activation-controlled reactions. At pH 1 and below, the main decomposition pathway for the S-nitroso species leads to formation of nitric oxide.]]> Sat 24 Mar 2018 07:35:23 AEDT ]]> Formation of environmentally persistent free radicals on α-Al₂O₃ https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29772 2O₃(0001) surface toward formation of phenolic EPFRs, under conditions relevant to cooling down zones of combustion systems. We show that, molecular adsorption of phenol on α-Al₂O₃(0001) entails binding energies in the range of −202 kJ/mol to −127 kJ/mol. The dehydroxylated alumina catalyzes the conversion of phenol into its phenolate moiety with a modest activation energy of 48 kJ/mol. Kinetic rate parameters, established over the temperature range of 300 to 1000 K, confirm the formation of the phenolate as the preferred pathways for the adsorption of phenol on alumina surfaces, corroborating the role of particulate matter in the cooling down zone of combustion systems in the generation of EFPRs.]]> Sat 24 Mar 2018 07:30:33 AEDT ]]> A theoretical study on the pyrolysis of perfluorobutanoic acid as a model compound for perfluoroalkyl acids https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25659 Sat 24 Mar 2018 07:28:09 AEDT ]]> Computational study of the oxidation and decomposition of dibenzofuran under atmospheric conditions https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:4437 Sat 24 Mar 2018 07:22:47 AEDT ]]> Quantum chemical and kinetic study of formation of 2-chlorophenoxy radical from 2-chlorophenol: unimolecular decomposition and bimolecular reactions with H, OH, Cl, and O₂ https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:4438 Sat 24 Mar 2018 07:22:47 AEDT ]]> Theoretical study of reaction pathways of dibenzofuran and dibenzo-p-dioxin under reducing conditions https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:3410 Sat 24 Mar 2018 07:21:36 AEDT ]]> Quantum chemical investigation of formation of polychlorodibenzo-p-dioxins and dibenzofurans from oxidation and pyrolysis of 2-chlorophenol https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:3500 Sat 24 Mar 2018 07:20:36 AEDT ]]> Formation of PCDD/Fs in oxidation of 2-chlorophenol on neat silica surface https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:24331 p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from their precursors. We have identified 2,6-dichlorophenol (2,6-DCPh), 2,4-dichlorophenol (2,4-DCPh), and 2,4,6-trichlorophenol (2,4,6-TriCPh), but have detected no chlorinated benzenes (CBzs). The detected chlorinated and nonchlorinated DD/Fs comprise dibenzo-p-dioxin (DD), 1- and 2-monochlorodibenzo-p-dioxin (1-, 2-MCDD), 1,6-, 1,9-, 1,3-dichlorodibenzo-p-dioxin (1,6-, 1,9-, 1,3-DCDD), 4-monochlorodibenzofuran (4-MCDF), and 4,6-dichlorodibenzofuran (4,6-DCDF) at the reaction temperatures of 350 and 400 °C. However, at a lower reaction temperature, 250 °C, we have detected no PCDD/Fs. We have demonstrated that neat silica surfaces catalyze the generation of PCDD/Fs from chlorophenols at the upper range of the catalytic formation temperature of PCDD/F. The present finding proves the generation of PCDD/Fs on particles of fly ash, even in the absence of transition metals.]]> Sat 24 Mar 2018 07:16:37 AEDT ]]> Oxidation of dibenzo-p-dioxin: formation of initial products, 2-methylbenzofuran and 3-hydro-2-methylenebenzofuran https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23823 Sat 24 Mar 2018 07:12:50 AEDT ]]> A mechanistic and kinetic study on the decomposition of morpholine https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22300 Sat 24 Mar 2018 07:11:06 AEDT ]]> Thermochemical parameters and pKa values for chlorinated congeners of thiophenol https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22299 a values based on gas phase deprotonation free energies and calculated solvation energies for chlorinated thiophenol molecules and chlorinated thiophenolate anions. Calculated pK_a values are in good agreement with limited available experimental measurements.]]> Sat 24 Mar 2018 07:11:06 AEDT ]]> Formation of environmentally-persistent free radicals (EPFR) on α-Al₂O₃ clusters https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:31130 Mon 11 Mar 2019 12:07:37 AEDT ]]>