@article{d'hennezel_ollis_2001, title={Surface prechlorination of anatase TiO(2) for enhanced photocatalytic oxidation of toluene and hexane}, volume={84}, ISSN={["0018-019X"]}, DOI={10.1002/1522-2675(20011114)84:11<3511::AID-HLCA3511>3.0.CO;2-K}, abstractNote={We report the influence of prechlorination of TiO2 powder on the activity for the photocatalyzed oxidation of hydrocarbons (toluene, hexane) and oxygenates (acetone, butan-1-ol). Water- and HCl-pretreated catalyst are prepared by impregnation of TiO2 powder in H2O and in HCl solutions, respectively, followed by drying at room temperature. X-Ray photoelectron spectroscopy (XPS) analysis demonstrates the surface prechlorination efficiency: 1 g of TiO2 impregnated with 3 ml of 3n HCl solution results in a chlorine surface concentration of 1.6%. Prechlorination results in a photo-oxidation-rate enhancement for toluene and hexane, no change for butan-1-ol, and inhibition for acetone. This pattern is the same as that demonstrated earlier by us when these reactants are co-fed with the chlorine source trichloroethylene (TCE).}, number={11}, journal={HELVETICA CHIMICA ACTA}, author={d'Hennezel, O and Ollis, DF}, year={2001}, pages={3511–3518} }
 @article{d'hennezel_pichat_ollis_1998, title={Benzene and toluene gas-phase photocatalytic degradation over H(2)O and HCL pretreated TiO(2): by-products and mechanisms}, volume={118}, ISSN={["1010-6030"]}, DOI={10.1016/S1010-6030(98)00366-9}, abstractNote={Photocatalytic oxidations of toluene and benzene in air were carried out over water (TiO2/H2O) and HCl (TiO2/HCl) pretreated TiO2 as this latter pretreatment enhances the toluene removal rate. The main purpose was to identify intermediate products. No gas-phase by-products were detected by direct GC/FID analysis under our conditions despite the high aromatic concentration (50 mg m−3) and the short contact time (ms); this result illustrates an attractive capability of this air purification method. Adsorbed intermediate products recovered by extraction from the used photocatalysts were the same over TiO2/H2O and TiO2/HCl; i.e. no chlorinated products were found in this latter case. Benzoic acid, benzaldehyde, and benzyl alcohol were three major toluene intermediate products identified; trace derivatives of these products and of toluene that were monohydroxylated on the ring were also detected in catalyst extract samples. The benzene major by-product was phenol which was accompanied by hydroquinone and 1,4-benzoquinone. Acetic and formic acids were also formed from both benzene and toluene. For both aromatics, a water extraction of the used photocatalysts permitted separation of a yellow viscous material that settled between water and TiO2 after centrifugation. We have not identified the products contained in this material but believe them to be polymeric products which may be at the origin of the decreased photocatalytic activity of used TiO2 with respect to fresh TiO2. Finally, we discuss the photocatalytic oxidation pathways.}, number={3}, journal={JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY}, author={d'Hennezel, O and Pichat, P and Ollis, DF}, year={1998}, month={Nov}, pages={197–204} }
 @article{duffaud_d'hennezel_peek_reysenbach_kelly_1998, title={Isolation and characterization of Thermococcus barossii, sp. nov., a hyperthermophilic Archaeon isolated from a hydrothermal vent flange formation}, volume={21}, ISSN={["0723-2020"]}, DOI={10.1016/S0723-2020(98)80007-6}, abstractNote={A new hyperthermophilic microorganism, Thermococcus barossii, was isolated from rock fragments of a hydrothermal vent flange formation, located along the East Pacific Rise of the Juan de Fuca Ridge. This organism is obligately anaerobic and grows over a temperature range of at least 60–92 °C in artificial seawater-based media, containing elemental sulfur, tryptone and yeast extract. The addition of a maltooligosaccharide mixture and tungsten to this medium improved growth to some extent. At the Topt for growth (82.5 °C), cell densities as high as 4×108 cells/ml could be obtained in 18-liter batch fermentations, with a doubling time of approximately 40 minutes, if culture access to elemental sulfur was sufficient. In continuous culture at the same temperature, comparable cell densities could be obtained but only at slower growth rates. Morphologically, T. barossii is coccoid-shaped, forming irregularly-shaped spheres; under optimal conditions, these coccoids become more regular and smaller, a characteristic of other hyperthermophilic archaea. Negatively-stained preparations showed no pili or flagella associated with the cell surface. 16S rRNA sequencing reveals that T. barossii is most similar to Thermococcus celer (99.7%). Yet, further comparisons with T. celer showed that T. barossii is a new Thermococcus species: different growth temperature optimum (82.5 °C vs. 88 °C), obligate requirement for sulfur, higher G+C content (60% vs. 56.7%) and 47.7% DNA-DNA hybridization. The nucleotide and translated amino acid sequence for the gene encoding a DNA polymerase from T. barossii was compared to sequences of related genes from other Thermococcales. The polymerase phylogenies were congruent with those obtained from the 16S rRNA phylogenetic analyses. Based on the high degree of similarity among members of the genus Termococcus for the criteria used thus far, aspects of enzymology may be an important mechanism of differentiating one species from another.}, number={1}, journal={SYSTEMATIC AND APPLIED MICROBIOLOGY}, author={Duffaud, GD and d'Hennezel, OB and Peek, AS and Reysenbach, AL and Kelly, RM}, year={1998}, month={Mar}, pages={40–49} }
 @misc{luhm_d'hennezel_duffaud_jolly_kelly_ting_1997, title={Purified Thermococcus barossii DNA polymerase}, volume={5,602,011}, number={1997 Feb. 11}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Luhm, R. A. and d'Hennezel, O. B. and Duffaud, G. D. and Jolly, J. F. and Kelly, R. M. and Ting, E. Y.}, year={1997} }
 @article{dhennezel_ollis_1997, title={Trichloroethylene-promoted photocatalytic oxidation of air contaminants}, volume={167}, ISSN={["0021-9517"]}, DOI={10.1006/jcat.1997.1552}, abstractNote={The prospects for photocatalytic purification and treatment of air depend centrally on finding conditions for which the apparent photoefficiency for contaminant disappearance is near or above 100%. We recently demonstrated that destruction of a low photoefficiency contaminant, toluene, by addition of a high photoefficiency compound, trichloroethylene, could raise the toluene photoefficiency to provide 100% conversion in a single pass, fixed bed illuminated catalyst, using a residence time of about 5–6 ms. The present paper establishes the generality of this TCE enhancement of contaminant rate and photoefficiency by examining the photocatalytic oxidation of various common contaminants at 50 mg/m3in air, including alcohols, aldehydes, ketones, aromatics, and chloroalkanes using near-UV-illuminated titanium dioxide powder in a flow reactor, in the absence and presence of trichloroethylene (TCE). Compounds exhibiting TCE rate promotion were toluene, ethylbenzene,m-xylene, methyl ethyl ketone (MEK), acetaldehyde, butyraldehyde, methyltert-butyl ether (MTBE), methyl acrylate, 1,4-dioxane, and hexane. Rate inhibition by TCE was exhibited for acetone, methylene chloride, chloroform, and 1,1,1-trichloroethane. TCE presence had almost no effect on the benzene and methanol rates. Butanol and vinyl acetate single component conversions were 100% under our standard low flow rate conditions; increasing the flow rate quenched TCE conversion in the presence of butanol, and therefore no TCE enhancement effect could be noted.}, number={1}, journal={JOURNAL OF CATALYSIS}, author={dHennezel, O and Ollis, DF}, year={1997}, month={Apr}, pages={118–126} }