SOFC Anodes Based on Infiltration of La0.3Sr0.7TiO3 (2008)
Lee, Shiwoo, Kim, Guntae, Vohs, John M, Gorte, Raymond J
Composites formed by infiltration of 45 wt % La0.3Sr0.7TiO3 (LST) into 65% porous yttria-stabilized zirconia (YSZ) were examined for application as solid oxide fuel cell (SOFC) anodes. Although LST...
Efficient Reduction of CO2 in a Solid Oxide Electrolyzer (2008)
Bidrawn, F., Kim, G., Corre, G., Irvine, J. T.S., Vohs, John M, Gorte, Raymond J
The electrolysis of CO2 has been examined in a solid oxide electrolyzer (SOE) using a ceramic electrode based on La0.8Sr0.2Cr0.5Mn0.5O3 (LSCM), infiltrated into a yttria-stabilized zirconia scaffold...
Engineering Composite Oxide SOFC Anodes for Efficient Oxidation of Methane (2008)
Kim, Guntae, Corre, G., Irvine, J. T. S., Vohs, John M, Gorte, Raymond J
Ceramic anodes for solid oxide fuel cells SOFCs were prepared by aqueous impregnation of nitrate salts to produce composites with 45 wt % La0.8Sr0.2Cr0.5Mn0.5O3 (LCSM)in a 65% porous...
SOFC Anodes Based on LST-YSZ Composites and on Y0.04Ce0.48ZrM0.48O2 (2008)
Kim, Guntae, Gross, Michael D, Wang, Wensheng, Vohs, John M, Gorte, Raymond J
The properties of solid oxide fuel cell (SOFC) anode functional layers prepared by impregnation of 1 wt % Pd and 10 wt % ceria into porous scaffolds of either Y0.04Ce0.48Zr0.48O2 (CZY) or composites...
A Thermodynamic Investigation of the Redox Properties of Ceria-Titania Mixed Oxides (2008)
Zhou, Gong, Hanson, Jonathan, Gorte, Raymond J
Ceria-titania solutions with compositions of Ce0.9Ti0.1O2 and Ce0.8Ti0.2O2 were prepared by the citric-acid (Pechini) method and characterized using x-ray diffraction (XRD) for structure, coulometric...
Wang, Wensheng, Gorte, Raymond J, Vohs, John M
The performance of solid oxide electrolysis (SOE) cells while operating in the natural gas assisted steam electrolysis (NGASE) mode was evaluated. The SOE cells used yttria-stabilized-zirconia (YSZ)...
Bidrawn, Fred, Lee, S., Vohs, John M, Gorte, Raymond J
The influence of ionic conductivity on the performance of solid oxide fuel cell cathodes was studied for electrodes prepared by infiltration of 40 wt % La0.8Ca0.2FeO3 (LCF) La0.8Sr0.2FeO3 (LSF) and...
Hydrogen Production via CH4 and CO Assisted Steam Electrolysis (2007)
Wang, Wensheng, Vohs, John M, Gorte, Raymond J
Porous composite anodes consisting of a yttria-stabilized zirconia (YSZ) backbone that was impregnated with CeO2 and various amounts of metallic components including Cu, Co and Pd were fabricated....
A Study of Cerium-Manganese Mixed Oxides for Oxidation Catalysis (2007)
Zhou, Gong, Shah, Parag R, Gorte, Raymond J
Cerium-manganese mixed oxides with compositions of Ce0.5Mn0.5O1.75 and Ce0.8Mn0.2O1.9 were prepared by the citric-acid (Pechini) method and their catalytic properties were compared to CeO2 and Mn2O3....
Woo, Leta Y, Martin, L. Peter, Glass, Robert S, Wang, Wensheng, Yong, Sukwon, Gorte, Raymond J, ...
The role of metal (Au, Pt, and Ag) electrodes in yttria-stabilized zirconia (YSZ) electrolyte-based impedancemetric nitric oxide (NO) sensors is investigated using impedance spectroscopy and...
Preparation of SOFC Anodes by Electrodeposition (2007)
Jung, Sukwon, Vohs, John M, Gorte, Raymond J
Anodes for solid oxide fuel cells (SOFCs) have been prepared by electrodeposition of either Co or Ni into a layer of porous yttria-stabilized zirconia (YSZ), 60 µm thick. The YSZ, having 65%...
An Examination of SOFC Anode Functional Layers Based on Ceria in YSZ (2007)
Gross, Michael D, Vohs, John M, Gorte, Raymond J
The properties of solid oxide fuel cell (SOFC) anode functional layers prepared by impregnation of ceria and catalytic metals into porous yttria-stabilized zirconia (YSZ) have been examined for...
A Support Layer for Solid Oxide Fuel Cells (2007)
Ahn, Kipyung, Jung, Sukwon, Vohs, John M, Gorte, Raymond J
The use of a perforated, ceramic layer, laminated on top of a porous electrode, as a support structure for solid oxide fuel cells is described. The support layer can be used on either the anode or...
Oxidation Enthalpies for Reduction of Ceria Surfaces (2007)
Zhou, Gong, Shah, Parag R, Montini, Tiziano, Fornasiero, Paolo, Gorte, Raymond J
The thermodynamic properties of surface ceria were investigated through equilibrium isotherms determined by flow-titration and coulometric-titration measurements on high-surface-area ceria and ceria...
Oxidation entropies and enthalpies of ceria-zirconia solid solutions (2007)
Zhou, Gong, Shah, Parag R, Kim, Taeyoon, Fornasiero, Paolo, Gorte, Raymond J
The thermodynamic redox properties for a series of ceria-zirconia solid solutions have been measured by determining their oxidation isotherms between 873 and 1073 K. Isotherms were obtained using...
The Stability of LSF-YSZ Electrodes Prepared by Infiltration (2007)
Wang, Wensheng, Gross, Michael D, Vohs, John M, Gorte, Raymond J
Composite electrodes were prepared by adding 40 wt % La0.8Sr0.2FeO3 (LSF) into porous yttria-stabilized zirconia (YSZ) and their performance was studied as a function of time and calcination...
Woo, Leta Y, Martin, L. Peter, Glass, Robert S, Gorte, Raymond J
An electrochemical cell [Au/yttria-stabilized zirconia (YSZ)/Au] serves as a model system to investigate the effect of O2 and NOx. Possible mechanisms responsible for the response are presented. Two...
A Strategy for Achieving High-performance with SOFC Ceramic Anodes (2007)
Gross, Michael D, Vohs, John M, Gorte, Raymond J
A proposal that high solid oxide fuel cell (SOFC) anode performance can be achieved by using a very thin, catalytically active functional layer, with a noncatalytic conduction layer, has been tested....
Deactivation of Ceria-Based SOFC Anodes in Methanol (2007)
Kim, Taeyoon, Ahn, Kipyung, Vohs, John M, Gorte, Raymond J
The performance and stability of Cu-ceria-YSZ (yttria-stabilized zirconia) and carbon-ceria-YSZ, solid-oxide-fuel-cell (SOFC) anodes were examined in neat (100%) methanol at 973K and compared to the...
Gross, Michael D, Vohs, John M, Gorte, Raymond J
Cu-based, solid oxide fuel cell (SOFC) electrodes were modified by electrodeposition of Co. The addition of only 5-vol% Co by electrodeposition significantly improved the thermal stability compared...
Recent Progress in SOFC Anodes for Direct Utilization of Hydrocarbons (2007)
Gross, Michael D, Vohs, John M, Gorte, Raymond J
There would be significant advantages to having anodes for solid oxide fuel cells (SOFC) that were capable of directly utilizing hydrocarbon fuels. Because conventional Ni-based anodes catalyze the...
A Comparison of LSM, LSF, and LSCo for Solid Oxide Electrolyzer Anodes (2006)
Wang, Wensheng, Huang, Yingyi, Jung, Sukwon, Vohs, John M, Gorte, Raymond J
Composite electrodes of yttria-stabilized zirconia (YSZ) with La0.8Sr0.2MnO3 (LSM), La0.8Sr0.2FeO3 (LSF), and La0.8Sr0.2CoO3 (LSCo) were prepared and tested as solid oxide electrolyzer (SOE) anodes...
Electrodeposition of Cu into a Highly Porous Ni/YSZ Cermet (2006)
Jung, Sukwon, Gross, Michael D, Gorte, Raymond J, Vohs, John M
The electrochemical deposition of Cu into 0.12 cm and 60 µm thick, highly porous 65 vol % Ni/yttria-stabilized zirconia (YSZ) cermets was investigated. An electrochemical cell in which the...
A Study of Carbon Formation and Prevention in Hydrocarbon-Fueled SOFC (2006)
Kim, Taeyoon, Liu, G., Boaro, Marta, Vohs, John M, Gorte, Raymond J, ...
The formation and removal of the carbonaceous deposits formed by n-butane and liquid hydrocarbons, such as n-decane and proprietary light and heavy naphthas, between 973 and 1073 K on YSZ and...
An investigation of NOx storage on Pt-BaO-Al2O3 (2006)
Zhou, Gong, Luo, T., Gorte, Raymond J
A series of samples containing 5-wt% or 20-wt% BaO on γ-Al2O3 with different loadings of Pt were prepared and examined for their NO2 adsorption properties using temperature programmed desorption...
Jung, Sukwon, Lu, Chun, He, Hongpeng, Ahn, Kipyung, Gorte, Raymond J, Vohs, John M
In this study, we report on how different impregnation procedures affect the distribution and morphology of the Cu component in Cu/CeO2/YSZ composite anodes and how this affects anode performance....
Structure and Thermal Stability of Ceria Films Supported on YSZ(100) and α-Al2O3(0001) (2005)
Costa-Nunes, Olga, Ferrizz, Robert M, Gorte, Raymond J, Vohs, John M
The morphology and reducibility of vapor-deposited ceria films supported on yttria-stabilized zirconia (100) (YSZ(100)) and α-Al2O3(0001) single crystals were studied using X-ray photoelectron...
Recent Developments Towards Commercialization of Solid Oxide Fuel Cells (2005)
Solid oxide fuel cells (SOFC) are receiving an increasing level of attention for both small- and large-scale applications due their high fuel flexibility compared to other types of fuel cells. This...
Costa-Nunes, Olga, Gorte, Raymond J, Vohs, John M
In this study the performance of a solid oxide fuel cell (SOFC) with Cu-CeO2-yttria-stabilized zirconia (YSZ) was compared to an SOFC with Ni-YSZ anode while operating on H2, CO, and syngas fuels....
A Comparison of Ceria and Sm-Doped Ceria for Hydrocarbon Oxidation Reactions (2004)
The oxidation of methane, ethane, propane, and n-butane has been studied over CeO2 and Ce0.8Sm0.2Ox (SDC) catalysts. The rates for methane and ethane were found to be indistinguishable over the two...
Lu, C., An, Sungbae, Worrell, Wayne L., Vohs, John M, Gorte, Raymond J
In this study, we compare the performance of SOFC having composite Cu-based anodes but made with the following low-temperature electrolytes: samaria-doped ceria (SDC), Sr- and Mg-doped lanthanum...
Characterization of YSZ-YST Composites for SOFC Anodes (2004)
He, Hongpeng, Huang, Yingyi, Vohs, John M, Gorte, Raymond J
Porous composites of Sr0.88Y0.08TiO3-δ (YST) and yttria-stabilized zirconia (YSZ) were formed by tape-casting methods and examined as potential anodes for SOFC. Even after calcination to 1773 K, the...
Recent Developments on Anodes for Direct Fuel Utilization in SOFC (2004)
Gorte, Raymond J, Vohs, John M, McIntosh, Steven
This paper reviews recent work on SOFC anode fabrication at the University of Pennsylvania. In this work, anode fabrication is based on the preparation of a porous YSZ matrix, into which electronic...
Characterization of SO2-Poisoned Ceria-Zirconia Mixed Oxides (2004)
CeO2, ZrO2, and a series of CexZr1-xO2 catalysts with 1 wt% Pd were exposed to fixed exposures of SO2 under oxidizing environments and then characterized by FTIR, pulse-reactor studies with CO and...
The Acylation of Propene by Acetic Acid over H-[Fe]ZSM-5 and H-[Al]ZSM-5 (2004)
Kresnawahjuesa, Oferi, Gorte, Raymond J, White, David
We have studied the vapor-phase reaction of acetic acid with propene over H-[Al]ZSM-5 and H-[Fe]ZSM-5 molecular sieves between 425 and 600 K, for acetic acid partial pressures of 25 to 50 Torr, with...
Low-Temperature Fabrication of Oxide Composites for Solid-Oxide Fuel Cells (2004)
He, Hongpeng, Huang, Yingyi, Regal, Juleiga, Boaro, Marta, Vohs, John M, Gorte, Raymond J
Composites of yttria-stabilized zirconia (YSZ) with Sr-doped LaCrO3 (LSC) and Sr-doped LaMnO3 (LSM) were prepared by impregnation of a porous YSZ matrix with aqueous solutions of the appropriate...
Deactivation of the Water-Gas-Shift Activity of Pd/Ceria by Mo (2004)
Zhao, S., Luo, T., Gorte, Raymond J
The effect of surface Mo on the water-gas-shift (WGS) activity of Pd/ceria was studied. A series of 1-wt% Pd catalysts, with varying Mo content, were prepared from supports obtained by aqueous...
Measurement of Electrode Overpotentials for Direct Hydrocarbon Conversion Fuel Cells (2004)
Krishnan, Venkatesan V., McIntosh, Steven, Gorte, Raymond J, Vohs, John M
Cathodic and anodic overpotentials were measured using current interruption and AC impedance spectroscopy for two separate solid oxide fuel cells (SOFCs). The fuel cells used yttria-stabilized...
Advanced Anodes for High Temperature Fuel Cells (2004)
Atkinson, A., Barnett, S., Gorte, Raymond J, Irvine, J. T.S., McEvoy, A. J., Mogensen, M. B, ...
Fuel cells will undoubtedly find widespread use in this new millennium in the conversion of chemical to electrical energy, as they offer very high efficiencies and have unique scalability in...
The Activity of Fe-Pd Alloys for the Water-Gas Shift Reaction (2004)
The role of Fe promoters has been investigated on Pd/ceria, Pt/ceria and Rh/ceria catalysts for the water-gas shift (WGS) reaction in 25 Torr of CO and H2O, under differential reaction conditions....
The Effect of Oxide Dopants in Ceria on n-Butane Oxidation (2003)
Solid solutions of CeO2 with Yb2O3, Y2O3, Sm2O3, Gd2O3, La2O3, Nb2O5, Ta2O5, and Pr6O11 were prepared by sol-gel methods. All of the samples exhibited a single, cubic phase in x-ray diffraction and...
Ferrizz, Robert M, Gorte, Raymond J, Vohs, John M
The interaction of sulfur with ceria under highly reducing conditions was investigated. The phase boundary between CeO1.83 and Ce2O2S was determined for temperatures between 873 and 1073 K. This data...
The effect of adding oxide promoters, at monolayer coverages, to Pd/ceria catalysts was studied for the water-gas-shift reaction in 25 torr each of H2O and CO under differential conditions. Oxides of...
Novel SOFC anodes for the direct electrochemical oxidation of hydrocarbons (2003)
Gorte, Raymond J, Vohs, John M
Recent developments in solid-oxide fuel cells (SOFC) that electrochemically oxidize hydrocarbon fuels to produce electrical power without first reforming them to H2 are described. First, the...
Synthesis of Highly Porous Yttria-Stabilized Zirconia by Tape-Casting Methods (2003)
Boaro, Marta, Vohs, John M, Gorte, Raymond J
Porous ceramics of Y2O3-stabilized ZrO2 (YSZ) were prepared by tape-casting methods using both pyrolyzable pore formers and NiO followed by acid leaching. The porosity of YSZ wafers increased in a...
A Mechanistic Study of Sulfur Poisoning of the Water-Gas-Shift Reaction Over Pd/Ceria (2003)
The effect of sulfur on the water-gas-shift (WGS) activity of Pd/ceria catalysts has been studied using steady-state rate measurements, pulse-reactor studies, and FTIR. After exposing Pd/ceria to SO2...
Deactivation Mechanisms for Pd/Ceria During the Water-Gas Shift Reaction (2002)
Wang, X., Gorte, Raymond J, Wagner, J. P
The mechanism responsible for the irreversible deactivation of ceria-supported precious metals for the water-gas-shift reaction has been investigated through accelerated aging tests. It is shown that...
Kresnawahjuesa, Oferi, Gorte, Raymond J, Oliveira, D. De, Lau, L. Y.
A method based on amine decomposition has been developed for measuring the Brønsted-acid site densities using a standard, tubular reactor with an on-line gas chromatograph (GC). After exposing a...
An Examination of Sulfur Poisoning on Pd/Ceria Catalysts (2002)
Luo, T., Vohs, John M, Gorte, Raymond J
The species formed by exposure of a Pd/ceria catalyst to SO2 under various conditions have been studied using temperature-programmed desorption (TPD) and FTIR. For adsorption of SO2 between 298 and...
TPD and XPS Investigation of the Interaction of SO2 with Model Ceria Catalysts (2002)
Ferrizz, Robert M, Gorte, Raymond J, Vohs, John M
The interaction of SO2 with model thin film ceria catalysts was studied using temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). During TPD of ceria samples that had...
An Examination of Lanthanide Additives on the Performance of Cu-YSZ Cermet Anodes (2002)
McIntosh, Steven, Vohs, John M, Gorte, Raymond J
The effect of various lanthanide additives on the performance of Cu-YSZ (yttria-stabilized zirconia), cermet anodes for solid-oxide fuel cells (SOFCs) was investigated at 973 K for H2 and the direct...
Kresnawahjuesa, Oferi, Kühl, G. H, Gorte, Raymond J, Quierini, C. A.
The adsorption and reaction properties of an Al-free H-[Fe]ZSM-5 were examined and compared to an H-[Al]ZSM-5 sample with the same site density. H-[Fe]ZSM-5 was shown to have Brønsted-acid sites...
Kim, Hyuk, Da Rosa, Calvin, Boaro, Marta, Vohs, John M, Gorte, Raymond J
Porous Y2O3-stabilized ZrO2 (YSZ) samples were synthesized by preparing NiO/YSZ composites by tape casting and calcining at 1800 K, reducing the NiO to nickel in H2 at 973 K, and finally leaching the...
Novel SOFC Anodes for the Direct Electrochemical Oxidation of Hydrocarbon (2002)
Gorte, Raymond J, Kim, H., Vohs, John M
This paper describes recent developments in solid-oxide fuel cells (SOFC) that use Cu-based cermets as the anode for direct oxidation of hydrocarbon fuels, including liquids such as gasoline, to...
Removal of Tetramethylammonium Cations from Zeolites (2002)
Kresnawahjuesa, Oferi, Olson, D. H, Gorte, Raymond J, Kühl, G. H
Zeolite α (high-silica LTA), a potential shape-selective catalyst, is synthesized in the presence of tetramethylammonium (TMA) ions. Since TMA+ ions are incapable of forming olefins at low...