Showing papers in "Journal of Catalysis in 1997"

TL;DR: In this article, the selective CO oxidation reaction on Pt/γ-Al2O3-insimulated reformer gas (75% H2; the rest is N2) was investigated over a wide range of CO concentrations (0.02-1.5%).

TL;DR: In this article, a 2 wt% Mo/ZSM-5 catalyst was used for the dehydroaromatization of methane to benzene in the absence of an added oxidant.

TL;DR: In this article, a detailed description of the formation and the gasification of filamentous carbon is given, and a thermodynamic basis for the different solubilities is provided, where the segregation of carbon, taking place at the gas side of the nickel particle is added as one of the steps in the global mechanism of carbon filament formation and gasification.

TL;DR: In this paper, the interaction of methane with unsupported and supported molybdenum compounds (Mo, MoO2, Mo3, Mo2C, and MoC(1−x)) has been investigated at 973 K. ZSM-5 was used as a support.

TL;DR: In this paper, the adsorption of NO and NH3 on MnOx/Al2O3 catalysts, used for the low temperature selective catalytic reduction of NO, was studied separately by use of TPD (with labelled compounds) and FTIR.

TL;DR: In this article, the utilization of mechanical milling for the preparation of catalysts based on ceria structurally modified with zirconia is presented, and it is shown that room-temperature high-energy ball milling is an effective tool for the synthesis of nanophase CeO2−ZrO2solid solution in a wide composition range.

TL;DR: In this article, the mechanism of the selective catalytic reduction of NO with NH3 over low loaded MnOx/Al2O3 catalysts has been investigated using TPRD, FTIR, and step-response studies with labeled components.

TL;DR: In this article, the activities of 2 and 6 wt% Ag/Al2O3 catalysts for lean NO reduction with C3H6 were compared, and the difference in the behavior of the two catalysts was attributed to the much higher Ag dispersion for the 2 wt % than the 6 Wt % sample, such that the oxidation states of Ag were different under reaction conditions.

TL;DR: In this article, the authors used in situ XRD, in situ EXAFS, and FTIR spectroscopy with carbon monoxide as a molecular probe to study the reduction properties of Co species in silica supported Fischer-Tropsch catalysts.

TL;DR: In this paper, a method of preparing "overexchanged" FeZSM-5 catalysts is described that minimizes oxidation of Fe2+to Fe3+ during base-exchange and inhibits the formation of Bronsted sites.

TL;DR: In this article, a 4-h reduction under H2 at 573 K compared to either 473 or 673 K, gave the highest specific activity for furfural and crotonaldehyde hydrogenation over an unpromoted copper chromite catalyst.

TL;DR: In this paper, the selectivity of catalysts with small and large metal particles was investigated for the hydrogenation of crotonaldehyde via the carbonyl bond in the presence of coordinatively unsaturated Ti cations in these oxide particles.

TL;DR: In this paper, a dynamic microkinetic model of the methanol synthesis reaction over Cu/ZnO catalysts is described based on surface science measurements and it includes the dynamic changes in particle shape and active surface area which have recently been observed byin situEXAFS measurements to take place upon change in the redox potential of the reaction gas.

TL;DR: In this article, in situ infrared spectroscopy with the aim of understanding the nature of the species involved in methanol synthesis and the dynamics of the formation and consumption of these species.

TL;DR: In this paper, a detailed comparative analysis of the N2O decomposition over Co-, Fe-, and Cu-ZSM-5 was made, and the effect of partial pressure of N 2O, O 2, CO, and NO, the space time, and temperature have been investigated.

TL;DR: In this paper, XRD and TEM were used to measure the particle sizes of the various phases of the CeO 2 -Zr oxide solid solution and found that the particle size of the supported particulate phase decreased with increasing zirconium loading, but a discrepancy was noted between the XRD results and the TEM results.

TL;DR: The hydrogenation activity of Pt supported on two mesoporous MCM-41 samples differing in their chemical composition has been studied by following the kinetics of the hydrogenation of naphthalene at 225-275°C reaction temperature and 5.0 MPa total pressure.

TL;DR: In this paper, the catalytic activity is determined by the accessibility of Pt on the Pt-ZrO2perimeter, which is explained in terms of the CO2activation via carbonate species on the support which must bein the proximity of the Pt particles to react with the methane activated on the metal.

TL;DR: In this paper, the kinetics of elementary surface reactions involved in the reforming of methane to synthesis gas over supported nickel were studied using transient isotopic methods, and an overall model that describes the reactions of methane with steam and CO2 in microkinetic terms was constructed based on these rate constants and on previously published steam reforming and CO 2methanation data.

TL;DR: In this article, a large-pore SAPO-5 and a medium-POR SAPO were synthesized using a hydrothermal method, and they were characterized by chemical analysis, XRD, SEM, IR, TPD of NH 3, and MAS NMR; Pt dispersion was measured by H 2 adsorption.

TL;DR: In this paper, a transient kinetic study of CO2activation and methanation over M/CeO2 has also been conducted, which involves activation of CO 2on a surface Ce3+site with formation of CO followed by oxidation of Ce 3+to Ce4+.

TL;DR: In this article, a rigorous kinetic model for the formation of filamentous carbon on a nickel catalyst by methane cracking is derived, where the experimental study was performed in an electrobalance unit.

TL;DR: In this article, the insertion of trivalent cations into the lattice of Ce0.6Zr0.4O2solid solution improves the oxygen storage capacity at low temperatures by decreasing the temperature of the reduction in the bulk of the solid solution compared to the undoped sample.

TL;DR: In this article, the surface-enhanced Raman spectroscopy (SERS) was combined with X-ray photoelectron spectroscopic (XPS) to study the oxidation of ruthenium at ambient pressure (1 atm) and elevated temperatures (25-300°C) and the SERS probe provided in-situ vibrational information regarding surface oxide bonding.

TL;DR: In this paper, the authors investigated the Zr-O and Ce-O local structure in Rh/Ce0.5Zr0.6O2 by means of EXAFS and Raman spectroscopy.

TL;DR: In this article, the authors show that up to 73% of the template in MCM-41 can be removed by extraction with solutions of an acid or salt in ethanol, and the resulting catalysts show high activity for the acetylation of 2-methoxynaphthalene.

TL;DR: In this article, the addition of platinum to the catalyst enhances selectivity and activity of aldehydes, based on the involvement of lattice oxygen (viz, a Mars and Van Krevelen mechanism) and the spillover of activated hydrogen from the platinum to an oxide.

TL;DR: In this paper, the acid activity of the solid tungsten/zirconia can be affected by the catalyst preparation method, and it is shown that refluxing of the hydrous zirconias prior to tengsten impregnation gives a catalyst with higher surface area than the nonrefluxed material, but with the same strong acid site density, as determined by n -pentane isomerization activity.

TL;DR: In this paper, the S-BET method, XRD, XPS, and FTIR were used to characterize silica and alumina-supported zirconia samples.