Development of Novel Anode material for Intermediate Temperature SOFC (IT-SOFC)

We thank the Engineering and Physical Sciences Research Council (EPSRC)/ H2FC Supergen (EP/J016454/1, EP/K015540/1) and the Royal Society (WRMA 2012/R2) for support.The present work envisages application of titanium oxycarbide as a possible anode material for intermediate temperature solid oxide fuel cells (IT-SOFC). Titanium oxycarbide samples (TiOxC1-x with x = 0.2 - 0.8) were prepared by reaction-sintering of TiO and TiC powders under vacuum at 1500 C for 5 h. Basic studies on TiOxC1-x (x = 0.2-0.8) with respect to phase purity and stability under oxidizing and reducing environments were carried out. The compatibility of titanium oxycarbide with intermediate-temperature electrolyte material (Ce0.9Gd0.1O3-δ) was studied. The electrochemical properties of planar cells using Ce0.9Gd0.1O3-δ as electrolyte and employing TiO0.2C0.8 and La0.8Sr0.2Co0.2Fe0.8O3-δ based anode and cathode materials were investigated.PostprintPeer reviewe

Exsolution of Fe-Ni alloy nanoparticles from (La,Sr)(Cr,Fe,Ni)O3 perovskites as potential oxygen transport membrane catalysts for methane reforming

Authors acknowledge support from the EPSRC for Platform Grant EP/K015540/1 and EPSRC Capital for Great Technologies Grant EP/L017008/1.(La0.75Sr0.25)(Cr0.5Fe0.5−xNix)O3 perovskites were investigated as potential catalysts for oxygen transport membranes for methane reforming applications. XRD was performed to study the structural changes that took place when Fe was partially substituted by Ni, in both oxidising and reducing environments. TGA measurements demonstrated that the oxygen deficiency of these perovskites under reducing conditions was enhanced by increasing the level of Ni doping, due to the reduction of the Fe3+/Fe4+ and Ni2+ species to lower cation valences. SEM and TEM-EDX analyses showed that upon reduction exsolution of bimetallic Fe–Ni alloy nanoparticles took place on the surface of the perovskite, which was beneficial for the catalyst's activity. The optimum stoichiometry was the (La0.75Sr0.25)(Cr0.5Fe0.35Ni0.15)O3 perovskite, which during catalytic testing, demonstrated 72% CH4 conversion, which was 20 times higher than that of the initial perovskite.PostprintPeer reviewe

Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO1-xCx)

Titanium oxides and carbides are often considered as electrode materials in energy conversion and storage devices due to their high potential conductivity and good stability. Titanium monoxide and titanium carbide have structures that can both be described as rocksalt with the same cubic close packed titanium sublattice with oxygen and carbon, respectively, occupying the octahedral interstices; however, the oxide is characterised by extensive defects on both sublattices whilst the carbide is stoichiometric and might be considered as an interstitial metal. Despite the anticipated very different natures of the oxide and carbide sublattices, these two phases actually form a complete solid solution. In the present investigation, we carefully characterise this titanium oxycarbide solid solution, reporting on the crystal structure, magnetic and electronic conduction properties. Titanium oxycarbide powders (TiO1-xCx with x = 0 ≤ x ≤ 1) have been prepared by solid state reactions of TiO and TiC powder under controlled environments at elevated temperatures. X-ray diffraction and pycnometric density measurements illustrate the gradual transition of the crystal structure of titanium oxycarbides from a vacancy containing rock-salt structure of TiO to fully occupied TiC with increase in carbon content in the oxycarbide lattice. The variation of the lattice parameter of the oxycarbide crystal as a function of the carbon content has been found to be non-linear which can be attributed to variations in the level of vacancies present in metal as well as non-metal sublattices. The existence of a short-range ordering of anion vacancies in oxycarbide with a nominal composition of TiO0.5C0.5 where half of oxygen of TiO is replaced by carbon has been confirmed by selected-area electron diffraction studies. Low temperature magnetic and conductivity measurements confirm that all oxycarbide compositions are Pauli paramagnetic and good metallic conductors.PostprintPeer reviewe

Next generation PCR microfluidic system

Stokes Bio, founded in 2005, develops innovative microfluidic technologies. In 2008 in collaboration with Monsanto, an application driven development for a high-throughput instrument in the detection and characterisation of Single Nucleotide Polymorphisms (SNPs) in agricultural crops was initiated. Stokes technology is designed to generate aqueous nanolitre scale droplets of reagents and samples, wrapped in a carrier fluid from standard microtitre plates and to mix them using Stokes Bio’s proprietary liquid bridge mixers. Following mixing the complete assay is transferred in the carrier fluid through the use of a continuous flow system, to a flow through thermal cycler and an optical reading station. This poster summarises results collated using the Stokes Bio genotyping platform currently based in Monsanto. Data will be presented to illustrate the dynamic capabilities of the instrument, highlighting the enhanced sensitivity and reproducibility of PCR in droplet format compared to well-based technologies

B-site doping of lanthanum strontium titanate for solid oxide fuel cell anodes

In this study the properties of the compounds La0.33Sr0.67Ti0.92X0.08O3+δ where X = Al3+, Ga3+, Fen+, Mg2+, Mnn+ and Sc3+, have been investigated in the search for alternative solid oxide fuel cell anodes. The choice of dopant controls the structure, redox properties, conductivity and electrocatalytic properties of the compound

Development of Novel Anode material for Intermediate Temperature SOFC (IT-SOFC)

The present work envisages application of titanium oxycarbide as a possible anode material for intermediate temperature solid oxide fuel cells (IT-SOFC). Titanium oxycarbide samples (TiOxC1-x with x = 0.2 - 0.8) were prepared by reaction-sintering of TiO and TiC powders under vacuum at 1500 C for 5 h. Basic studies on TiOxC1-x (x = 0.2-0.8) with respect to phase purity and stability under oxidizing and reducing environments were carried out. The compatibility of titanium oxycarbide with intermediate-temperature electrolyte material (Ce0.9Gd0.1O3-δ) was studied. The electrochemical properties of planar cells using Ce0.9Gd0.1O3-δ as electrolyte and employing TiO0.2C0.8 and La0.8Sr0.2Co0.2Fe0.8O3-δ based anode and cathode materials were investigated

Scale Up and Anode Development for La-Doped SrTiO₃ Anode-Supported SOFCs

The possibility of developing large solid oxide fuel cell (SOFC) stacks based upon 25cm2 ceramic oxide anode-supported cells is investigated. Planar fuel cells comprising strontium titanate-based anode support impregnated with active catalysts were prepared using a combination of deposition techniques. The fuel cell tests performed in a semisealed rig have shown power densities of 185mWcm-2 at 850 degrees C using humidified hydrogen as fuel and air as oxidant. The structure and evolution of the catalytically active impregnated materials-10mol% Gd-doped CeO2 and nickel- are analysed using electron microscopy at the end of the fuel cell test, revealing that a ceria and nickel layer surrounds the titanate backbone grains while similar to 50-150nm spherical-like nickel particles uniformly decorate this top layer.</p

Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO_1-xC_x)

Titanium oxides and carbides are often considered as electrode materials in energy conversion and storage devices due to their high potential conductivity and good stability. Titanium monoxide and titanium carbide have structures that can both be described as rocksalt with the same cubic close packed titanium sublattice with oxygen and carbon, respectively, occupying the octahedral interstices; however, the oxide is characterised by extensive defects on both sublattices whilst the carbide is stoichiometric and might be considered as an interstitial metal. Despite the anticipated very different natures of the oxide and carbide sublattices, these two phases actually form a complete solid solution. In the present investigation, we carefully characterise this titanium oxycarbide solid solution, reporting on the crystal structure, magnetic and electronic conduction properties. Titanium oxycarbide powders (TiO1-xCx with x = 0 ≤ x ≤ 1) have been prepared by solid state reactions of TiO and TiC powder under controlled environments at elevated temperatures. X-ray diffraction and pycnometric density measurements illustrate the gradual transition of the crystal structure of titanium oxycarbides from a vacancy containing rock-salt structure of TiO to fully occupied TiC with increase in carbon content in the oxycarbide lattice. The variation of the lattice parameter of the oxycarbide crystal as a function of the carbon content has been found to be non-linear which can be attributed to variations in the level of vacancies present in metal as well as non-metal sublattices. The existence of a short-range ordering of anion vacancies in oxycarbide with a nominal composition of TiO0.5C0.5 where half of oxygen of TiO is replaced by carbon has been confirmed by selected-area electron diffraction studies. Low temperature magnetic and conductivity measurements confirm that all oxycarbide compositions are Pauli paramagnetic and good metallic conductors