@article{silletti_adams_sigmon_nikolopoulos_spivey_lamb_2006, title={A novel Pd/MgAlOx catalyst for NOx storage-reduction}, volume={114}, ISSN={["1873-4308"]}, DOI={10.1016/j.cattod.2006.02.003}, abstractNote={A novel NOx storage-reduction catalyst consisting of Pd dispersed on a magnesium–aluminum oxide (MgAlOx) support is described. The MgAlOx support was prepared from a synthetic Mg/Al layered double hydroxide, and Pd bis-acetylacetonate (acac) was adsorbed onto the freshly calcined support from toluene. The Pd/MgAlOx catalyst was pretreated in either O2 or H2 at 500 °C to decompose the adsorbed [Pd(acac)2] and remove organic residues. NOx adsorption experiments were conducted at 300 °C using two gas mixtures: 500 ppm NO2, 6% O2 and 10% CO2 (bal. He) and 500 ppm NO, 500 ppm N2 and 5% O2 (bal. He). Temperature-programmed desorption (TPD) and diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS) evidence that NO2 adsorption on MgAlOx produces primarily surface nitrate species. The adsorption capacity of the support for NO + O2 is four-fold lower than for NO2. Temperature-programmed reduction (TPR) in flowing H2 demonstrates that surface nitrate and nitrite species on MgAlOx are reduced to N2 at 300–400 °C. The adsorption capacity of Pd/MgAlOx for NO + O2 is almost four-fold greater than MgAlOx evidencing a catalytic role of Pd in the NOx storage mechanism. TPR in flowing H2 indicates that the adsorbed NOx species are removed at very low temperatures (∼50 °C) suggesting that they are located near the catalytically active Pd sites.}, number={1}, journal={CATALYSIS TODAY}, author={Silletti, BA and Adams, RT and Sigmon, SM and Nikolopoulos, A and Spivey, JJ and Lamb, HH}, year={2006}, month={Apr}, pages={64–71} }
 @article{sirijaruphan_goodwin_rice_wei_butcher_roberts_spivey_2005, title={Effect of metal foam supports on the selective oxidation of CO on Fe-promoted Pt/gamma-Al2O3}, volume={281}, number={02-Jan}, journal={Applied Catalysis. A, General}, author={Sirijaruphan, A. and Goodwin, J. G. and Rice, R. W. and Wei, D. G. and Butcher, K. R. and Roberts, G. W. and Spivey, J. J.}, year={2005}, pages={18-} }
 @article{sirijaruphan_goodwin_rice_wei_butcher_roberts_spivey_2005, title={Metal foam supported Pt catalysts for the selective oxidation of CO in hydrogen}, volume={281}, number={02-Jan}, journal={Applied Catalysis. A, General}, author={Sirijaruphan, A. and Goodwin, J. G. and Rice, R. W. and Wei, D. G. and Butcher, K. R. and Roberts, G. W. and Spivey, J. J.}, year={2005}, pages={09-} }
 @article{wang_spivey_lamb_2005, title={NO decomposition over a Pd/MgO catalyst prepared from [Pd(acac)(2)]}, volume={56}, ISSN={["1873-3883"]}, DOI={10.1016/j.apcatb.2004.09.014}, abstractNote={A Pd/MgO catalyst was prepared by adsorption of palladium bis-acetylacetonate [Pd(acac)2] onto highly dehydroxylated MgO from toluene solution and subsequent reduction in flowing H2 at 300 °C. The resultant catalyst was characterized by Pd K-edge X-ray absorption fine structure (XAFS) spectroscopy, temperature-programmed desorption (TPD), and Fourier transform infrared (FTIR) spectroscopy of adsorbed NO. The adsorbed [Pd(acac)2] species decomposes on heating in H2 to form 20–25 Å supported Pd particles; however, organic residues from the acetylacetonate ligands remain on the catalyst surface. The FTIR spectrum of NO adsorbed on the reduced Pd/MgO catalyst at 25 °C contains one principal band at 1722 cm−1 due to atop Pd nitrosyl species. In situ XAFS of the Pd/MgO catalyst indicates that neither Pd oxidation nor particle sintering occurs during heating in flowing 1% NO/He to 300 °C. NO decomposition over the Pd/MgO catalyst was investigated using temperature-programmed reaction spectroscopy (TPRS) and steady-state activity measurements. During the initial TPRS cycle in flowing 1% NO/He, nearly complete NO consumption occurs at ∼270 °C due to oxidation of organic residues. O2 evolution commences at approximately 350 °C, and steady-state catalytic decomposition of NO to N2 and O2 occurs at 600 °C. Transient NO consumption during rapid cooling in 1% NO/He (after steady-state catalysis) is attributed to NOx adsorption on the Pd/MgO catalyst.}, number={4}, journal={APPLIED CATALYSIS B-ENVIRONMENTAL}, author={Wang, XQ and Spivey, JJ and Lamb, HH}, year={2005}, month={Apr}, pages={261–268} }
 @article{wang_sigmon_spivey_lamb_2004, title={Support and particle size effects on direct NO decomposition over platinum}, volume={96}, ISSN={["1873-4308"]}, DOI={10.1016/j.cattod.2004.05.003}, abstractNote={Supported Pt catalysts were prepared by ion exchange of Pt(II) tetraamine hydroxide [Pt(NH3)4(OH)2] onto SiO2, Al2O3, and TiO2 and by adsorption of Pt bis-acetylacetonate [Pt(acac)2] onto MgO. All the catalysts except Pt/TiO2 were characterized by in situ X-ray absorption fine structure (XAFS) spectroscopy after reduction at 300 °C in flowing H2, and the Pt/SiO2 and Pt/MgO catalysts were examined after subsequent exposure to 1% NO/He at 25–300 °C. NO decomposition pathways were investigated by temperature-programmed reaction spectroscopy (TPRS) using a 1% NO/He feed, and steady-state conversions for direct NO decomposition were measured at 600 °C. NO decomposition at low temperatures (200–400 °C) produces N2O and N2, and in situ XAFS spectroscopy indicates that the supported Pt particles are partially oxidized under these conditions. Over each catalyst, O2 production begins at ∼350 °C; N2O production declines above 400 °C; and N2 and O2 are the only detectable NO decomposition products at 600 °C. Nanometer-sized Pt clusters on SiO2 sinter during heating in 1% NO/He at 300 °C, whereas larger Pt particles supported on SiO2 and MgO are resistant to sintering under these conditions. The turnover frequency for direct NO decomposition over Pt/SiO2 catalysts is insensitive to Pt particle size. Pt/SiO2, Pt/Al2O3, and Pt/TiO2 catalysts have equivalent NO decomposition activities suggesting the absence of support effects for these metal oxides. In contrast, the NO decomposition activity of Pt supported on strongly basic MgO is significantly lower.}, number={1-2}, journal={CATALYSIS TODAY}, author={Wang, XQ and Sigmon, SA and Spivey, JJ and Lamb, HH}, year={2004}, month={Oct}, pages={11–20} }
 @article{roberts_chin_sun_spivey_2003, title={Preferential oxidation of carbon monoxide with Pt/Fe monolithic catalysts: interactions between external transport and the reverse water-gas-shift reaction}, volume={46}, ISSN={["1873-3883"]}, DOI={10.1016/j.apcatb.2003.07.002}, abstractNote={A series of Pt/Al2O3 catalysts, promoted with Fe and supported on 400 cpsi (cells per square inch) (62 cells/cm2) ceramic straight-channel monoliths, was synthesized and evaluated for preferential oxidation (PROX) of a low concentration of CO in the presence of a high concentration of H2. These catalysts were evaluated in an adiabatic reactor at a total pressure of 0.20 mPa inlet temperatures of 80–170 °C, and a space velocity of 30,000 h−1. The inlet gas composition was—H2: 42%, CO2: 9%, H2O: 12%, CO: 0–1.0%, O2: 0–1.0%, with N2 as the balance. For a catalyst containing 5 wt.% Pt in the washcoat, the carbon monoxide and oxygen conversions increased as the iron concentration in the washcoat was increased up to about 0.5 wt.% Fe. The reverse water-gas-shift (r-WGS) reaction played an important role in determining the outlet CO concentration. A catalyst with 1.6 g/in.3 (0.098 g/cm3) of an alumina washcoat containing 5 wt.% Pt/Al2O3 promoted with 0.5 wt.% Fe was selected for detailed investigation. The effects of both space velocity and linear velocity were studied. External transport was a significant resistance with this catalyst, at the above experimental conditions. The external resistances to heat and mass transfer, coupled with the effect of the r-WGS reaction, reduced the observed CO conversion and selectivity.}, number={3}, journal={APPLIED CATALYSIS B-ENVIRONMENTAL}, author={Roberts, GW and Chin, P and Sun, XL and Spivey, JJ}, year={2003}, month={Nov}, pages={601–611} }
 @article{zhao_sudsakorn_goodwin_jothimurugesan_gangwal_spivey_2002, title={Attrition resistance of spray-dried iron F-T catalysts: effect of activation conditions}, volume={71}, ISSN={["0920-5861"]}, DOI={10.1016/S0920-5861(01)00458-8}, abstractNote={The focus of the research reported herein was to investigate the effects of phase changes, as occur during Fe catalyst activation and Fischer–Tropsch synthesis, on Fe catalyst attrition resistance. Different activation conditions (CO, H2 or syngas) were applied prior to attrition testing to a selected spray-dried Fe catalyst containing 9.1 wt.% binder SiO2, which had been shown to have the highest attrition resistance in our early study of calcined catalysts. Although, XRD indicated that different Fe phase compositions resulted in the differently activated catalyst samples, chemical attrition was not observed for any of the samples. The BET surface areas of the activated samples were smaller than that of the calcined precursor but no significant changes in pore volume and particle size were found. The attrition resistances of the differently activated catalyst samples were found to be similar to that of the calcined catalyst for this spray-dried Fe catalyst. Attrition resistance was found previously to be governed by catalyst particle density, which has been shown earlier to relate to the SiO2 network in catalysts. It is therefore suggested that the type and concentration of SiO2 that is incorporated during the preparation of spray-dried Fe catalysts have a much more significant impact on catalyst attrition than Fe phase change during activation in the presence of CO, H2 or H2+CO.}, number={3-4}, journal={CATALYSIS TODAY}, author={Zhao, R and Sudsakorn, K and Goodwin, JG and Jothimurugesan, K and Gangwal, SK and Spivey, JJ}, year={2002}, month={Jan}, pages={319–326} }
 @article{jang_reynolds_boutonnet_spivey_2002, title={Catalysis and plasma technology - Preface}, volume={72}, ISSN={["0920-5861"]}, DOI={10.1016/S0920-5861(01)00490-4}, number={3-4}, journal={CATALYSIS TODAY}, author={Jang, BWL and Reynolds, JG and Boutonnet, M and Spivey, JJ}, year={2002}, month={Mar}, pages={171–171} }
 @misc{wilcox_roberts_spivey_2002, title={Thermodynamics of light alkane carboxylation}, volume={226}, number={1-2}, journal={Applied Catalysis. A, General}, author={Wilcox, E. M. and Roberts, G. W. and Spivey, J. J.}, year={2002}, pages={317–318} }
 @article{frankel_jang_spivey_roberts_2001, title={Deactivation of hydrodechlorination catalysts I. Experiments with 1.1.1-trichloroethane}, volume={205}, ISSN={["0926-860X"]}, DOI={10.1016/S0926-860X(00)00577-9}, abstractNote={In order to understand the cause(s) of catalyst deactivation, microreactor studies were carried out on the catalytic hydrodechlorination (HDC) of 1,1,1-trichloroethane (111-TCA) using a fixed-bed reactor divided into three segments. The catalysts studied were: ηδ-alumina, α-alumina, Pt/α-alumina, Pt/η-alumina, and Pt/ηδ-alumina. Experiments were carried out at atmospheric pressure over a temperature range of 423–623 K and at H2/111-TCA molar ratios between 10 and 99. Only the Pt-containing catalysts were able to remove all three Cl atoms from 111-TCA. However, increasing amounts of partially-dechlorinated compounds were formed as the Pt/ηδ-alumina and the Pt/η-alumina catalysts deactivated. The only product with ηδ-alumina was 1,1-dichloroethylene (11-DCE). The conversion of 111-TCA decreased more rapidly with time for Pt/ηδ-alumina than for ηδ-alumina without Pt. Much larger quantities of coke were formed on the Pt/ηδ-alumina than on the ηδ-alumina, at similar conditions. The ηδ-alumina was essentially completely regenerated by heating in flowing He at 773 K. The Pt/η-alumina was only partially regenerated by this technique. The apparent stability of the Pt/ηδ-alumina catalysts increased with increasing Pt concentration. Poisoning by hydrochloric acid, a reaction product, did not cause significant deactivation of either the ηδ-alumina or the Pt/ηδ-alumina catalysts.}, number={1-2}, journal={APPLIED CATALYSIS A-GENERAL}, author={Frankel, KA and Jang, BWL and Spivey, JJ and Roberts, GW}, year={2001}, month={Jan}, pages={263–278} }
 @article{frankel_jang_roberts_spivey_2001, title={Deactivation of hydrodechlorination catalysts II - Experiments with 1,1-dichloroethylene and 1,1-dichloroethane}, volume={209}, ISSN={["0926-860X"]}, DOI={10.1016/S0926-860X(00)00784-5}, abstractNote={In an earlier paper [K.A. Frankel, B.W.-L. Jang, J.J. Spivey, G.W. Roberts, Appl. Catal. A, in press], it was shown that certain alumina and Pt/alumina catalysts deactivated rapidly during the hydrodechlorination (HDC) of 1,1,1-trichloroethane (111-TCA) at temperatures between 423 and 623 K. Large quantities of coke were formed on these catalysts at some conditions. In the present research, the deactivation associated with four intermediates in the HDC of 111-TCA; 1,1-dichloroethylene (11-DCE), 1,1-dichloroethane (11-DCA), chloroethane, and ethylene, was investigated. Experiments were carried out with ηδ-alumina and 3% Pt/η-alumina at 423 and 523 K, atmospheric pressure, and at a H2/chlorinated hydrocarbon/He ratio of 10/1/89. The ηδ-alumina, without Pt, catalyzed the removal of one molecule of HCl from each of the saturated chlorocarbons. Deactivation of the ηδ-alumina was rapid with 111-TCA and 11-DCA, and relatively slow with chloroethane. There was no reaction over ηδ-alumina when 11-DCE was fed. The fresh Pt/η-alumina catalyst was able to remove all of the Cl from the chlorocarbons. This catalyst deactivated with 111-TCA and 11-DCA, but no deactivation was observed with 11-DCE and chloroethane. At comparable conditions, much more coke was deposited on the Pt/η-alumina catalyst with 111-TCA than with any of the other compounds. Hydrochloric acid did not appear to cause deactivation. A reaction scheme is proposed to summarize the major reaction pathways and to identify potential causes of catalyst deactivation.}, number={1-2}, journal={APPLIED CATALYSIS A-GENERAL}, author={Frankel, KA and Jang, BWL and Roberts, GW and Spivey, JJ}, year={2001}, month={Feb}, pages={401–413} }
 @article{frankel_spivey_roberts_2001, title={Mathematical model of the deactivation of Pt/alumina catalyst during the hydrodechlorination of 1,1,1-trichloroethane}, volume={139}, journal={Catalyst deactivation 2001: Proceedings of the 9th international symposium, Lexington, KY, USA, 7-10 October 2001 (Studies in surface science and catalysis;  139)}, publisher={Amsterdam; New York: Elsevier}, author={Frankel, K. A. and Spivey, J. J. and Roberts, G. W.}, editor={J. J. Spivey, G. W. Roberts and Davis, B. H.Editors}, year={2001}, pages={439–446} }
 @article{zhao_goodwin_jothimurugesan_gangwal_spivey_2001, title={Spray-dried iron Fischer-Tropsch catalysts. 1. Effect of structure on the attrition resistance of the catalysts in the calcined state}, volume={40}, ISSN={["0888-5885"]}, DOI={10.1021/ie000644f}, abstractNote={The use of Fe Fischer−Tropsch (F−T) catalysts in slurry bubble column reactors (SBCRs) has been problematic in the past because of their poor attrition resistance. Recently, we have reported the preparation of spray-dried Fe F−T catalysts having attrition resistance suitable for SBCR use, but the reason for this improvement was not clear. This paper focuses on research done to better understand the reason for the high attrition resistance of some of the Fe catalysts prepared. Understanding the relationship between the catalyst attrition resistance and composition/structure is important for the preparation of attrition-resistant Fe catalysts. In the present study, two series of spray-dried Fe F−T catalysts having the composition Fe/Cu/K/SiO2 but with different amounts of precipitated and/or binder SiO2 were investigated. All of the catalysts studied were evaluated in their calcined form. This was done to minimize any possible attrition due to Fe phase change (such as can occur during activation and F−T syn...}, number={4}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Zhao, R and Goodwin, JG and Jothimurugesan, K and Gangwal, SK and Spivey, JJ}, year={2001}, month={Feb}, pages={1065–1075} }
 @article{zhao_goodwin_jothimurugesan_gangwal_spivey_2001, title={Spray-dried iron Fischer-Tropsch catalysts. 2. Effect of carburization on catalyst attrition resistance}, volume={40}, ISSN={["0888-5885"]}, DOI={10.1021/ie0006458}, abstractNote={Spray drying has been recently used by this research team in the preparation of Fe Fischer−Tropsch catalysts with higher attrition resistance for use in slurry bubble column reactors. In the first paper in this series, the effects of the type, concentration, and network structure of SiO2 on the attrition resistance of two series of spray-dried Fe catalysts in their calcined state were explored and the dependence of catalyst attrition resistance on catalyst particle density was discussed. As a continuation of our previous effort, the effect of carburization on catalyst attrition resistance was studied and is presented in this paper. After carburization, the majority component of the catalysts, hematite (Fe2O3), was converted to iron carbides, mostly χ-carbide (Fe2C5). Breakage of individual catalyst particles and fines formation, which can be considered as evidence of chemical attrition, was only observed during carburization of the catalyst with low SiO2 concentration <9 wt %. With an increase in the tota...}, number={5}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Zhao, R and Goodwin, JG and Jothimurugesan, K and Gangwal, SK and Spivey, JJ}, year={2001}, month={Mar}, pages={1320–1328} }