Lionel Vayssieres National Institute for Materials Science
Enrico Traversa University of Rome "Tor Vergata"
Yasuhiro Tachibana RMIT University
Liejin Guo Xi'an Jiaotong University
International Center for Materials NanoArchitectonics, National Institute for Materials Science, Tsukuba, Japan
RMIT University, Australia
F1: Materials and Modeling for Photoelectrochemical Generation of Renewable Fuels I
Tuesday PM, April 26, 2011
Room 2005 (Moscone West)
9:30 AM - **F1.1
Catalytic Model Systems Studied by High-resolution, Video-rate Scanning Tunneling Microscopy.
Flemming Besenbacher 1 Show Abstract
1 Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus Denmark
The development of renewable, sustainable and green energy resources and the protection of the environment by reducing emission pollutants are two of the largest challenges for the human civilization within the next 50 years Besides the well-known energy resources that power the world today; petroleum, coal, and natural gas, active research and development exploring alternative energy resources such as solar, biomass, wind, and hydrogen is currently being performed. To realize the vision of a clean society and our vision of plentiful, low cost sustainable energy, research and innovation within the area of the rapidly expanding fields of nanoscience and nanotechnology, multi-disciplinary by nature involving physics, chemistry, biology, molecular biology, is mandatory. For decades single-crystal surfaces have been studied under ultra-high va-cuum (UHV) conditions as model systems for elementary surface processes. This “surface science approach” has contributed substantially to our understanding of the processes involved in especially catalysis. In this talk I will show how Scanning Tunneling Microscopy (STM) can reveal fundamental processes in relation to catalysis, and how we can extract quantitative information on surface diffusion of adatoms and molecules, identification of active sites and determination of new nanostructures with novel, catalytic properties from time-resolved, high-resolution STM images/movies (see www.phys.au.dk/spm). The atomic-scale information obtained may even lead to the design of new and improved catalysts in certain cases.
10:00 AM - **F1.2
U.S. Department of Energy Research and Development Efforts in Renewable Hydrogen Production via Photoelectrchemical Water Splitting.
Eric Miller 1 , Roxanne Garland 1 , Sara Dillich 1 Show Abstract
1 EERE, U.S. Department of Energy, Washington, District of Columbia, United States
The US Department of Energy (DOE) hydrogen production research and development portfolio focuses on low-cost, highly efficient and environmentally friendly production technologies based on diverse, domestic resources. Within the DOE, work on hydrogen production technologies integrates basic and applied research, as well as technology development and demonstration. The integration of basic and applied research is of particular importance in “transformational” production technologies, such as photoelectrochemical (PEC) hydrogen production, where scientific advances are needed for achieving the long-term DOE performance and cost targets. In the case of renewable hydrogen production via PEC solar water splitting, high solar-to-hydrogen conversion efficiency has been demonstrated to date on the laboratory scale, but only with high-cost, low-durability material systems. In order to identify and develop the appropriate high-efficiency, low-cost, durable and scalable PEC material systems, research and development efforts in the DOE EERE (Energy Efficiency and Renewable Energy) Office have keyed in on specific focus areas, including: 1) the engineering of solar energy absorption properties in PEC semiconductor materials, such as the bandgap lowering in stable metal oxides as well as bandgap raising in nanostructured sulfide catalysts; 2) the engineering of PEC solid-liquid interfaces for optimal reaction rates and stability, such as surface nitrogenation in III-V semiconductor systems; 3) the standardization of PEC measurement and reporting methodologies, using national and international peer-review process, for facilitating research progress; and 4) the design and analysis of integrated PEC device and system configurations for scalable hydrogen production. As described in this presentation, all of these research and development areas rely heavily on collaborative efforts among academia, industry and national laboratory partners, utilizing state of the art resources in materials theory, synthesis, characterization and analysis. The collaboration extends nationally among research programs supported by the DOE EERE as well as Office of Science; and internationally via networking through the International Energy Agency’s Hydrogen Implementation Agreement Annex-26. Key and encouraging accomplishments resulting from the collaborative work are highlighted in this presentation.
10:30 AM - **F1.3
An International Effort to Develop Photoelectrochemical (PEC) Hydrogen Production Research Standards and Methods.
Huyen Dinh 1 , Zhebo Chen 2 , Todd Deutsch 1 , Alan Kleiman-Shwarsctein 3 , Arnold Forman 4 , Nicolas Gaillard 5 , Roxanne Garland 6 , Kazuhiro Takanabe 7 , Kazunari Domen 7 , Clemen Heske 8 , Mahendra Sunkara 9 , Eric McFarland 3 , Eric Miller 5 , John Turner 1 , Tom Jaramillo 2 Show Abstract
1 Hydrogen Technologies and Systems Center, National Renewable Energy Laboratory, Golden, Colorado, United States, 2 Department of Chemical Engineering, Stanford University, Stanford, California, United States, 3 Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, United States, 4 Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California, United States, 5 Hawaii Natural Energy Institute, University of Hawaii, Honolulu, Hawaii, United States, 6 Fuel Cell Technologies Program, U.S. Department of Energy, Washington, District of Columbia, United States, 7 Department of Chemical System Engineering, University of Tokyo, Tokyo Japan, 8 Department of Chemistry, University of Nevada Las Vegas, Las Vegas, Nevada, United States, 9 Department of Chemical Engineering, University of Louisville, Louisville, Kentucky, United States
Photoelectrochemical (PEC) water splitting for hydrogen production is a promising technology. In the expanding field of PEC hydrogen production, the standardization of screening methods and reporting has emerged as a necessity. Because of significant technical challenges and limited research and development resources, PEC researchers and funding organizations need quantified, accurate, and consistent characterization results to justify resource priorities. Additionally, widely accepted standard PEC material characterization protocols will help researchers from different groups to characterize PEC materials and report comparable results. A common understanding of the materials, along with the ability to screen them quickly while guiding research toward the most promising materials, will more efficiently identify materials that meet PEC requirements. The U.S. Department of Energy (DOE) PEC working group has written documents that define appropriate methods and reporting standards for PEC research. The methods and definitions presented are the product of a DOE supported effort to form a consensus among a number of experienced researchers in this area from various DOE-supported laboratories, including national labs and academic institutions, and other international partners. This guide aims to help accelerate materials development by establishing standards for methods, definitions, and reporting protocols that will enable direct cross-comparison of materials’ properties and performance and thus facilitate knowledge transfer on a global scale. An additional motivation to develop standard protocols is to provide guidance on what are acceptable and unacceptable (e.g. erroneous) practices in the characterization of PEC materials as well as the measurement and reporting of efficiencies and the stability of such devices.Standard procedures for PEC characterization techniques for planar photoelectrode materials with a focus on single band gap absorbers are presented in the form of a suggested flowchart to guide researchers in their efforts to discover new candidates. Presented on the U.S. Department of Energy (DOE) Energy Efficiency and Renewable Energy (EERE) website is an in-depth discussion of the procedures outlined in the flow chart, including information on the basic principle behind each type of characterization, the associated laboratory techniques and experimental set-ups, the type of data that can be extracted, and the potential pitfalls and limitations. Some of the standard methods discussed include UV-Vis, Mott-Schottky, photocurrent onset, incident photon conversion efficiency (IPCE), photocurrent spectroscopy, and stability.
11:00 AM - F1: PEC1
11:30 AM - **F1.4
Hydrogen Production from Photoelectrochemical Cells: Theoretical Considerations and Experimental Results.
John Turner 1 Show Abstract
1 , NREL, Golden, Colorado, United States
To date, no semiconducting material has been discovered that simultaneously meets all the criteria required for economical hydrogen production via light-driven direct water splitting. Considerable work has been directed at metal oxides due to their expected stability and low costs, unfortunately after 35 years of work little progress has been made, efficiencies for these oxides remains abysmally low. This is not surprising, in general when it comes to solar photoconversion, oxides have very poor electronic properties and thus there are no solid-state PV devices where an oxide is the active light absorbing material. For a viable material, semiconductors for photoelectrochemical water splitting must have the same fundamental internal quantum efficiency as the commercial high efficiency PV devices. Multi-component transition metal oxides are complex materials, making intuitive guesses impossible and a focused search very challenging. So to achieve suitable photo-electrode materials, the electronic properties of the materials and their response to defect formation must be understood. A computational approach may be the only approach that can give us the necessary insight into these mixed metal oxides and allow us to narrow the composition space leading us towards a successful material. The highest efficiency PV devices are III-V material based. The III-V nitride materials have shown excellent stability as evidenced by corrosion analysis; however, they show a significant decrease in overall conversion efficiency as compared to other non-nitride III-Vs. This report will discuss issues relating to metal oxides and summarize our efforts on III-V nitride materials and their application to tandem cells for photoelectrochemical water splitting.
12:00 PM - **F1.5
Electronic-structure Challenges in Modelling Materials for Energy Applications.
Nicola Marzari 1 Show Abstract
1 Department of Materials, University of Oxford, Oxford United Kingdom
Electronic-structure modeling has become a very powerful tool to understand, predict, or design the properties of complex materials and devices. It is also an imperfect tool, with many open and urgent challenges in our quest towards qualitative and quantitative accuracy, and in our ability to perform quantum simulations under realistic conditions.I'll describe a few case studies, focusing on electron-transfer excitations and transition-metal catalysts, trying to highlight challenges and successes in the field. Several of these challenges stem from the remnants of self-interaction in our electronic-structure framework, and I'll discuss first its effects and possible solutions. I'll also highlight how first-principles spectroscopies allow for an ever closer interaction with experiments, with special attention given to the theoretical calculation of magnetic spectra (NMR and EPR).
12:45 PM - F1.7
Evidence of Charge Separation in a Single Asymmetric Nanowire and Correlation to Its Ensemble Photoelectrochemical Performance.
Chong Liu 1 3 , Yunjeong Hwang 1 3 , Hoon Jeong 1 3 , Peidong Yang 1 2 3 Show Abstract
1 Department of Chemistry, University of California, Berkeley, Berkeley, California, United States, 3 Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States, 2 Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California, United States
Artificial photosynthesis consisting of semiconductor materials has been explored for more than three decades to store clean solar energy efficiently in the form of usable chemical energy such as hydrogen. Among all the efforts of improvement, the “Z-scheme” photoelectrochemical (PEC) cell imitates the biological photosynthesis which consists of two light-absorber centers relaying excited electron in nanoscale, thus giving higher theoretical efficiency than a single semiconductor system. However, up to now no direct evidence of charge flow across the semiconductor junction has been observed in “Z-scheme” although it is critical to enhance the solar energy conversion efficiency. Here, as a model system, we investigate the separation of photogenerated charges within a single asymmetric nanowire of dual-band gap configurations. For the first time, charge-separation under “Z-scheme” is observed on a single asymmetric nanowire by Kelvin probe force microscopy (KPFM), which opens up a method to investigate local potentials of nanomaterials for PEC reactions. Moreover, this local information of single nanowire is correlated with the ensemble photoelectrochemical performance of asymmetric nanowires, and some explanation is presented.
Lionel Vayssieres National Institute for Materials Science
Enrico Traversa University of Rome "Tor Vergata"
Yasuhiro Tachibana RMIT University
Liejin Guo Xi'an Jiaotong University
F4: Materials and Modeling for Biofuels Generation I
Wednesday AM, April 27, 2011
Room 2005 (Moscone West)
9:30 AM - **F4.1
Biofuels: The Role of Biodiesel and Improving Its Performance.
Gerhard Knothe 1 Show Abstract
1 , USDA / ARS / NCAUR, Peoria, Illinois, United States
Concerns about the availability and long-term supply of petroleum-derived fuels have caused the search for alternative sources of energy. Liquid fuels will for some applications be necessary for an indefinite period of time. Therefore, defining relevant feedstocks, producing fuels from these feedstocks and the properties of these fuels are critical issues. Fuels powering compression-ignition (diesel) and turbine (jet) engines are among these liquid energy sources. Biodiesel, defined as the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-based feedstocks plays a prominent role in this connection as alternative to petrodiesel fuels. Important issues facing biodiesel are feedstock supply as not enough vegetable oil is available to replace the whole petrodiesel market and the issue of fuel properties, especially cold flow and oxidative stability. The search for additional feedstocks coupled with the food vs fuel issue has increased interest in inedible oils derived from sources such as used cooking oils, jatropha and algae. However, biodiesel from these sources, as biodiesel derived from classical sources such as commodity vegetable oils, must meet performance criteria and this is not necessarily the case. Therefore, modifying the composition of biodiesel, i.e., its fatty ester profile, is a critical issue to enhance its use in the marketplace. Esters of specific fatty acids impart improved properties to biodiesel with esters of decanoic and palmitoleic acid displaying favorable properties for enrichment in biodiesel feedstocks. Renewable diesel is another fuel that can be obtained from triacylglycerol-based feedstocks. In its composition, i.e. alkane-type hydrocarbons, it more closely resembles petrodiesel fuel. While biodiesel is obtained from triacylglycerol-based feedstocks via a transesterification reaction using an alcohol in presence of a catalyst under mild conditions, renewable diesel can be obtained from such feedstocks via a hydrodeoxygenation reaction using hydrogen in presence of a catalyst under more severe conditions. Biodiesel and renewable diesel are compared regarding their production and properties and it is suggested that each fuel has a role to play in an alternative energy mix based on its properties.
10:00 AM - **F4.2
China’s Renewable Bio-liquid Industry: Survive or Die?
Ji Xing 1 Show Abstract
1 , Chinese Academy of Engineering, Beijing China
In this presentation, the discussion of renewable liquid fuel industry with bio-diesel and bio-ethanol as target is put forward, the technological upgrade and innovation related are introduced and evaluated, based on the development history, it shows an obvious trend of the intermittent and remittent “Malaria fever” development model, the reason to this development model are analyzed as well. The price of crude oil, corn and edible oil, policy factor and investment are the influential power for the direction of liquid bio-fuel industry. The key point for renewable liquid fuel industry is to survive or die? In order to answer this question, the stimulation policy packages basis and the rigid need of oil which is led to by them is analyzed, and the technological characteristic of the bio-diesel industry guarantee that it will not die, and strategic measures for survival are put forward as well, including enhancement of raw material supply, plant oil-rich trees and agricultures, import waste grease, make standard package, consume more renewable fuel, re-use the distillation residue, cultivate micro algae, develop esterification equipment.
10:30 AM - **F4.3
Biological Synthesis of C3-C8 Fuels and Chemicals.
James Liao 1 Show Abstract
1 , UCLA, Los Angeles, California, United States
Global energy and climate problems have stimulated increased efforts in synthesizing fuels and chemicals from renewable resources. Compared to the traditional biofuel, ethanol, higher alcohols offer advantages as fuel substitutes because of their higher energy density and lower hygroscopicity. In addition, these alcohols and related compounds are important chemical feedstocks. However, these alcohols cannot be synthesized economically using native organisms. Here we present a metabolic engineering approach using various microorganisms to produce higher alcohols including isobutanol, 1-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and other C3-C8 alcohols from renewable carbon source. This strategy leverages the host’s highly active amino acid biosynthetic pathway and diverts its 2-keto acid intermediates for alcohol synthesis. In particular, we have achieved high yield, high specificity production of isobutanol from glucose. We further developed a non-natural chain-elongation pathway to produce abiotic longer chain keto acids and alcohols by engineering the chain elongation activity of 2-isopropylmalate synthase and altering the substrate specificity of downstream enzymes through rational protein design. When introduced into E. coli, this non-natural biosynthetic pathway produces various long-chain alcohols with carbon number ranging from 5 to 8. This strategy has also been implemented in photosynthetic cyanobacteria, Synechococcus elongates to produce isobutyraldehyde and isobutanol directly from CO2, bypassing the need for plant or algal biomass processing.
11:30 AM - **F4.4
Impact of Ammonia Treatment on Natural Lignocellulosic Composites.
Shishir Chundawat 1 2 , Giovanni Bellesia 3 , Leonardo Sousa 1 , Nirmal Uppugundla 2 , Venkatesh Balan 1 2 , Paul Langan 4 , S. Gnanakaran 3 , Bruce Dale 1 2 Show Abstract
1 Chemical Engineering and Materials Science, Michigan State University, East Lansing, Michigan, United States, 2 Improved Processing (Area 2), Great Lakes Bioenergy Research Center, East Lansing, Michigan, United States, 3 Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States, 4 Biosciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, United States
Our world is slowly transitioning from a fossil fuel driven energy system to one that is supplied by a portfolio of more renewable and sustainable options. The annual solar energy captured by plants (e.g., cellulosic biomass) is nearly ten times the total energy used by humans. Thus cellulosic biomass will undoubtedly play an important role in our future energy portfolio. Valorization of cellulosic biomass is expensive and inefficient due to its native recalcitrance to enzymatic and microbial degradation. In this seminar, we highlight a promising strategy for overcoming biomass recalcitrance using ammonia (NH3) treatment to activate its deconstruction to fuels and chemicals. Ammonia pretreatments (e.g., AFEX or Ammonia Fiber Expansion) result in subtle chemical and structural changes within plant biomass that enhance enzyme accessibility to the embedded crystalline cellulose nanofibrils. Multi-modal characterization of these changes was carried out using various techniques (e.g., confocal microscopy, Raman spectroscopy, AFM, SEM, TEM, 3D electron tomography, NMR, ESCA) to gain insight into the factors influencing biomass recalcitrance and further elucidate the mechanism of ammonia based pretreatments. Ammonia can also alter the cellulose hydrogen bonding network from its native crystalline state (cellulose I) to produce an alloform (cellulose III) that has at least 5-fold higher hydrolysis rates than untreated cellulose. Theoretical studies (e.g., molecular dynamic simulations) were carried out to explain the differences in cellulose III versus native cellulose that are responsible for its remarkable material properties.
12:00 PM - **F4.5
Biocatalytic Coatings: A Material Science Enabled Approach to the Deployment of Biocatalysts for Biofuel Production.
Jimmy Gosse 1 , Jason Pratt 1 , Marc von Keitz 1 , Luca Zullo 1 Show Abstract
1 , BioCee Inc., St. Paul, Minnesota, United States
Biocatalytic coatings are biocomposite materials in which living microorganisms (the biocatalysts) are immobilized in thin nano-structured coatings. The coatings can be applied to a wide variety of surfaces and geometries, allowing the design of highly customized biocatalytic modules. These coating modules can overcome some of the key hurdles in traditional biocatalysis, specifically mass transfer limitations, mixing, and catalyst retention. At the same time, the coating technology was developed from the beginning with an eye towards scalability by making it compatible with a range of standard coating and printing technologies that are currently used on an industrial scale and for which equipment is readily available. A unique technical and economic advantage is the ability to store the coatings dry. This allows for the biocoating modules to be produced cost-effectively in a central location taking advantage of economies of scale and ship them dry to the location of deployment. Since the modules are ready for deployment upon arrival, it also eliminates the need for the user to maintain sophisticated biotechnology capabilities to grow and inoculate the microorganism. Our techno-economic analysis has shown that this technology can drastically reduce capital and operating cost of biocatalytic processes. The capital costs are driven down by replacing large stainless steel fermentation tanks with simple plastic units and also by reducing auxiliary equipment size such as air compressors. In this presentation, we will discuss recent developments in the application of biocatalytic coatings in the production of cellulosic ethanol and direct solar biofuels.
Lionel Vayssieres National Institute for Materials Science
Enrico Traversa University of Rome "Tor Vergata"
Yasuhiro Tachibana RMIT University
Liejin Guo Xi'an Jiaotong University
F9: Poster Session: Photovoltaics, Batteries, Fuel Cells and Photocatalysts for Renewable Fuels III
Thursday PM, April 28, 2011
Salons 7-9 (Marriott)
F8: Photovoltaics, Batteries, Fuel Cells and Photocatalysts for Renewable Fuels II
Thursday PM, April 28, 2011
Room 2005 (Moscone West)
2:30 PM - **F8.1
Nano-structured Materials for Next Generation Fuel Cells and Photoelectrochemical Devices.
Harry Tuller 1 , Johanna Engel 1 , Scott Litzelman 1 , Sean Bishop 1 Show Abstract
1 Materials Science and Engineering, MIT, Cambridge, Massachusetts, United States
Progress in achieving improved performance in the generation and utilization of hydrogen depends on our ability to identify materials with optimized electrical and (photo-)electrochemical performance. Given their high volume fraction of interfaces, high chemical stability and versatility (ionic, electronic, optical property control), nanocrystalline electroceramic materials are of growing interest for advanced energy conversion and storage technologies. As grain sizes decrease towards the Debye length and grain boundaries come in closer proximity, space charge properties begin to dominate, resulting in modified charge transport. Through systematic variation of grain boundary properties by heterogeneous in-diffusion of cations, the electronic and ionic carrier profiles in the space charge region may be altered. The relationships between space charge potential and defect profiles in the space charge regions are quantitatively analyzed, and implications for nano-ionic materials in thin film solid oxide fuel cells are discussed. From the standpoint of photoelectrochemical water splitting to generate hydrogen, optimizing band gap, band alignments and transport properties while retaining stability has remained a challenging objective. Novel nanocrystalline composite structures are introduced which exhibit features amenable to optimization of required properties.
3:00 PM - **F8.2
Small Would Be Beautiful: Materials Challenges for Fuel Cell Technology.
Walter Merida 1 2 Show Abstract
1 Clean Energy Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, 2 , Institute for Fuel Cell Innovation, National Research Council, Vancouver, British Columbia, Canada
Fuel cells are electrochemical energy conversion devices that enable high efficiencies and low or zero emission in a variety of applications. The proton exchange membrane fuel cell (PEMFC) is the most suitable technology implementation for automotive and portable power. The membrane electrode assemblies (MEAs) in modern PEMFC products lie at the interface between the macroscopic phenomena (fuel and oxidant delivery, humidification, etc.) and the micro- and nanoscopic processes (diffusion, migration, etc.) at each catalyst site. The MEAs must deliver reactants to and remove products from the fuel cell electrodes. They must also provide current collection with minimal thermal and electrical resistances.In the last decade, there has been significant progress in the optimisation of balance of plant components, overall stack topologies, and pre-commercial mass production schemes. However, two well-defined barriers to fuel cell product commercialisation remain: poor durability and high cost associated with basic repeating unit: the fuel cell. In most cases, the last remaining challenges (e.g., 50 percent reductions and increments in cost and durability, respectively) can be resolved with new material structures and properties at the micro- and nano-scales. This talk will review the demanding design constraints on automotive and portable PEMFC applications, and the current efforts toward improved materials and components.
3:30 PM - F8.3
Functional Ordered Mesoporous Metal Oxides and Carbons for Fuel Cell Catalysts.
Jinwoo Lee 1 , Jongmin Shim 1 , Eunae Kang 1 , Jin Kon Kim 1 , Songhun Yoon 2 Show Abstract
1 , POSTECH, Pohang Korea (the Republic of), 2 , KRICT, Daejon Korea (the Republic of)
Fuel cells are next-generation devices which convert chemical energy directly into electricity thorough the oxidation of hydrogen (or small organic molecules). In this presentation, to improve performance of fuel cell and tackle the problems related fuel cells, different kinds of mesostructured materials have been synthesized and used as a fuel cell catalyst (or catalyst supports). Ordered mesoporous WO3-X with a high conductivity comparable to a mesoporous carbon framework was synthesized and used as a cathode catalyst support for polymer-electrolyte-membrane fuel cells (PEMFC). Pt/mesoporous WO3-X exhibited a significant tolerance to cycling between 0.6 and 1.3 VNHE. Oxygen reduction reaction (ORR) catalysts, Pd3Pt1 nanoparticles with methanol tolerance, are supported on various carbon foam (MSU-F-C), CMK-3, and Vulcan XC-72. The large surface are and large pore size of MSU-F-C allowed a high degree of dispersion of Pd3Pt1 nanoparticles, resulting in high activity and improved methanol tolerance. Intermetallic PtPb nanoparticle loaded ordered mesoporous carbons with large pores (> 20 nm) were synthesized by the ‘one-pot’ self-assembly of lab-synthesized block copolymers. The electrochemical characterization of PtPb nanoparticle in ordered mesoporous carbon will be presented.
3:45 PM - F8.4
Carbon-encapsulated Nickel as a Passive, Non-noble, Hydrogen Fuel Cell Electrocatalyst.
Gareth Haslam 1 , Xiao Chin 1 , Tim Burstein 1 Show Abstract
1 Department of Materials Science and Metallurgy, University of Cambridge, Cambridge United Kingdom
We present details of the interesting properties of carbon-encapsulated nickel thin films which may be of use as a potential alternative to platinum-based hydrogen fuel cell anodes. Current fuel cell designs require the use of platinum as the electrocatalyst in order to provide sufficient current densities at low overpotentials. However, platinum is both expensive and scarce, restricting the large-scale production of fuel cell vehicles. Nickel, an effective electrocatalyst in alkaline fuel cells, is easily corroded in the harsh, acidic environment of the hydrogen fuel cell. Remarkably, we have shown that nickel can be passivated against corrosion by using direct current magnetron sputtering to prepare a thin film alloy of metal and carbon. Using high-resolution transmission electron microscopy has enabled us to determine the structure of this material which shows nanoparticles of crystalline nickel surrounded by layers of graphenic carbon. Further, we show that this material remains electrocatalytically active towards the fuel cell hydrogen oxidation reaction. Carbon on its own is not electrocatalytically active and so the activity must be due to the entrapped nickel. Possible mechanisms for this unusual behaviour are discussed.Nickel is not known to form a stable oxide in strongly acidic electrolytes nor at the anodic potentials applied here. We report that the anodic polarisation of a sputtered Ni-C electrode in hot 1.5 M sulphuric acid leads to a steadily decreasing current density, indicating that nickel can be passivated under conditions in which the oxide is unstable by co-depositing with carbon. This is thought to be a new form of passivation. We also demonstrate that this passivation is significantly durable.
4:30 PM - **F8.5
Solar Hydrogen Production from Water by Hematite Photoelectrode Catalysts.
Hironori Arakawa 1 , Mitsuru Kasama 1 , Takeshi Yamaguchi 1 Show Abstract
1 Department of Industrial Chemistry, Tokyo University of Science, Tokyo Japan
We report here the solar hydrogen production by α-Fe2O3 photoelectrode prepared by spin-coating of an ethanol solution of α-Fe2O3 nano-particles.Fe(NO3)3/9H2O and PVP (polyvinylpyrrolidone) were dissolved in N,N-dimethylform-amide (DMF). The solution was heated at 180 °C by a Teflon-lined stainless steel autoclave. α-Fe2O3 particles were prepared from solutions with different molar ratio of iron salt to PVP of 1:0.005 (sample A), 1:0.01 (sample B), 1:0.02 (sample C) and 1:0.03 (sample D). After reaction, the solutions were concentrated and solvent was replaced by ethanol.α-Fe2O3 photoelectrodes were prepared by spincoating of an ethanol solution of α-Fe2O3 particles on FTO glass, followed by calcination. Photocurrent measurement was conducted using a three-electrode or two-electrode system with 0.1M aq. NaOH as electrolyte, Ag/AgCl as reference, and Platinum wire as counterelectrode. The irradiation source was solar simulator (AM 1.5, 100mW/cm2). The incident photon to current convertion efficiency (IPCE) was measured using light from a 300W Xe lamp monochromatized by cut-off filters and bandpass filters.The diffraction peaks attributed to α-Fe2O3 were observed in all films. An increase of PVP amount resulted in an increase of particle size. The estimated particle size of sample A, B, C and D were about 35 nm, 50 nm, 60 nm and 80 nm, re-spectively. Many clear grain boundaries were observed in sample A, but in sample B-D, not so many boundaries were observed. From this observation, it is clear the amount of PVP influences improvement of interconnection among particles. Fig.2 shows the I-V curves of four α-Fe2O3 photoelectrodes under simulated sunlight. At 1.5 V vs. NHE, the photocurrent of sample A, B, C and D were 0.014, 0.13, 0.68 and 0.71 mA/cm2, respectively. Sample C and D showed high activity, though the surface areas are small. This result suggests activity (photocurrent) was influenced by improvement of interconnection among particles. IPCE curves of α-Fe2O3 film (sample C) at 1.2 V and 1.5 V vs. NHE were measured. The maximum IPCEs at 400nm were 10.7% and 4.9%, respectively. It is clear the prepared α-Fe2O3 can utilize the light up to 600 nm which is absorption edge of α-Fe2O3 semiconductor. Photoelectrochemical cell of two-electrode system was employed to measure evolved H2 and O2. H2 and O2 evolved with the stoichiometric ratio under applied bias. This result shows α-Fe2O3 photoelectrodes could convert lightenergy to chemical energy. α-Fe2O3 photoelectrodes for solar hydrogen production were prepared by spin-coating of ethanol solution of α-Fe2O3 particles synthesized from Fe(NO3)3, PVP and DMF by solvothermal method. Water splitting activity of α-Fe2O3 photoelectrode was much dependent on the Fe:PVP ratio and the best was obtained by Fe:PVP=1:0.02. Water splitting by simulated solar light using α-Fe2O3 photoelectrode was examined and H2 and O2 evolved in the stoichiometric ratio.
5:00 PM - F8.6
Surface Modification of α-Fe2O3 Nanorod Array Photoanodes for Improved Light-induced Water Splitting.
Shaohua Shen 1 , Coleman Kronawitter 2 , Liejin Guo 1 , Samuel Mao 2 Show Abstract
1 Department of Thermal Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China, 2 Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States
Compared to other metal oxide semiconductors as potential photoelectrodes for photoelectrochemical water splitting, α-Fe2O3 (hematite) has the advantage such as the small band gap energy of ~2.0 eV, chemical stability, widespread availability and innocuity. Unfortunately, the ultrafast recombination of the photogenerated carriers and the poor minority charge carrier mobility lead to a short hole diffusion length in α-Fe2O3, which allows only holes created close to the electrolyte interface to oxidize water. Hence, the overall photocurrents produced by solar light have been severely limited. In spite of this, aiming to shortening the hole transfer distance, many research groups have obtained relatively high efficiency with nanostructured α-Fe2O3 photoanodes. α-Fe2O3 nanorod array photoelectrodes were reported to favor the fast generation, transfer and collection of photogenerated electrons, which resulted in the enhanced photocurrents. On the other hand, doping with Si, Ti, Pt, Mo, Cr, Zn, and Ge among other atoms have displayed positive effects on the efficiency of α-Fe2O3 photoanodes. These have been mostly attributed to the improved charge conductivity. Surface decoration of α-Fe2O3 photoanodes has proved to be another achievement for the improvement of PEC efficiency by providing surface photooxidation sites. In this study, α-Fe2O3 nanorod array photoanodes were fabricated by a low-temperature aqueous chemical growth (ACG) thin film processing technique, and modified by surface doping of metal ions or surface decoration of metal oxides via a spin coating and annealing process. For the surface doping of α-Fe2O3 nanorods, β-FeOOH nanorods were firstly obtained via ACG, and then coated with a thin layer of precursor solution (WO3 sol, Cr3+, Co2+, etc.) by spin coating, while α-Fe2O3 nanorods instead were coated with the layer of precursor solution for the preparation of metal oxides (WO3, Cr2O3, CoO, Mn3O4, etc.) surface-decorated α-Fe2O3 nanorod array photoanodes. As the followed final step, annealing in air is necessary to obtain these two kinds of surface modified α-Fe2O3 photoanodes. In our primary research, the photocurrents of α-Fe2O3 nanorod array photoanodes were greatly enhanced by surface doping of W6+. The SEM results showed that the α-Fe2O3 film kept the original morphology of nanorods and there were no WO3 nanoparticles observed on the surface of α-Fe2O3 nanorods. This means that WO3 was doped in the shallow surface of α-Fe2O3 nanorods, considering the β-FeOOH nanorods were only coated by a thin layer of precursor WO3 sol before annealing, which might result in enhanced efficiency of PEC water splitting by retarding charge recombination and by promoting the surface reaction rate of photogenerated holes with water. Further investigation on surface modification of α-Fe2O3 nanorod array photoanodes is currently under investigation in our laboratory.
5:15 PM - F8.7
Extremely Thin Absorbers for Photoelectrochemical Water Splitting.
Hen Dotan 1 , Avner Rothschild 1 Show Abstract
1 Materials Engineering, Technion - Israel Institute of Technology, Haifa Israel
Hematite (α-Fe2O3) is one of the best candidate photoanode materials for photoelectrochemical cells for water splitting because it displays a unique combination of visible light absorption, stability in aqueous solutions and low cost. The major drawback of hematite photoanodes is low incident-photon-to-current efficiency (IPCE), which has been attributed to low activity for water oxidation and short life time of photogenerated minority carriers. The former deficiency can be rectified by catalysis and the latter one requires complicated nanostructuring to achieve efficient light harvesting and charge separation. The highest solar to hydrogen conversion efficiency reported for hematite photoanodes was achieved with nanostructured thick films (700 nm) produced by APCVD and catalyzed with IrO2 nanoparticles.1 The photocurrent measured at an applied potential of +1.23 V versus RHE under AM1.5G 100 mW/cm2 simulated sunlight conditions was slightly above 3 mA/cm2, about a quarter of the maximum theoretical limit (12.6 mA/cm2). The main loss is attributed to bulk recombination, which is still high (~80%) even with state-of-the-art nanostructured thick films.2 In this work we present an alternative approach for achieving high solar to hydrogen conversion efficiency with semiconducting metal-oxide photoelectrodes, using hematite photoanodes as a case study. Instead of nanostructured thick layers (~1 μm) we propose using extremely thin absorbers (ETA) of few 10’s of nm. To achieve efficient light absorption the ETA should be deposited in thin film form on back reflecting electrodes and their thickness optimized to enhance constructive interference within the film. We calculated the optimal thickness of hematite ETA photoanodes to be 42 nm, and the expected photocurrent can be as high as 5.8 mA/cm2 under optimal injection conditions and with a perfectly reflecting back electrode (R = 1). To test this approach we deposited hematite thin films (doped with 1% Ti) of different thicknesses between 20 and 200 nm on platinised fused silica substrates, and measured their optical and photoelectrochemical properties. The platinised substrates were found to be semi-reflective (R = 0.5), reducing the theoretical efficiency by a factor of three compared to fully-reflective substrates (R = 1). A maximum photocurrent of 2 mA/cm2 was obtained for 44 nm films and the thickness-dependence was in line with model calculations. For comparison, the maximum photocurrent obtained with hematite films deposited on transparent substrates (TEC15) was 1.5 mA/cm2 (for film thickness of 160 nm). 1 S. D. Tilley, M. Cornuz, K. Sivula and M. Grätzel, Angew. Chem. Int. Ed. 2010, 49, 6405 –6408.2 H. Dotan, K. Sivula, M. Grätzel, A. Rothschild and S. C. Warren, Energy Environ. Sci. (under review).
5:30 PM - F8.8
Synthesis and Properties of Nanostructured Hematite Thin Film and its Modified Nanoarchitectures for Solar Water Spiltting.
Debajeet Bora 1 2 , Artur Braun 1 , Rolf Erni 3 , Giuseppino Fortunato 4 , Thomas Graule 1 5 , Edwin Constable 2 Show Abstract
1 Laboratory for High Performance Ceramics, Empa.Swiss Federal Laboratory for Material Sciecne and Technology, Dubendorf, 0, Switzerland, 2 Department of Chemistry, University of Basel, Basel, 0, Switzerland, 3 Electron Microscopy center, Empa.Swiss Federal Laboratory for Material Science and Technology, Dubendorf, 0, Switzerland, 4 Laboratory for Advanced Fibers, Empa.Swiss Federal Laboratory for Material Science and Technology, St. Gallen, 0, Switzerland, 5 , Technische Universität Freiberg, Freiberg Germany
Nanostructured hematite film has long been studied for solar water oxidation process. To enhance the efficiency of photolectrochemical water splitting, hematite physical properties has widely been tuned either by doping or growing the morphology along particular direction. For instance, different hierarchical nanoarchitectures was fabricated in order to get enhanced efficiency and higher surface area for photon harvesting whereby faster carrier transport through bulk level occurs due to the absence of any defect. Here we developed a very simple and effective method to convert a dip coated hematite film into 3-D nanoflowers with hexapod architecture on a carpet of nanorod. Before performing the post modification step, hematite thin films are first synthesized by a non aqueous chemical route and post annealing technique. The substrate used for the film deposition was FTO coated tin oxide. The synthesized film was further characterized by XRD to determine the presence of hematite phase. From XRD result it was found that the diffraction peaks arise mainly from the dense SnO2 coating on the glass substrate. There is only one strong peak due to hematite, namely the (110) reflection (in hexagonal coordinates).FESEM further signifies the highly porous architecture of the films with a thickness of 630 nm. Also, from the dark and light current density measurement in a three electrode cappuccino cell with 1 M NaOH, the photocurrent density was found out to be 140μA/cm2 which confirmed that the films deposited were photo active. Finally, the modified film has good photoresponse in comparison to the pristine one and increased by two fold. HRTEM and SAED pattern of the modfied film further signified the hierchical assembly and the proper crystallographic alignment of flower like superstructure .The BET measurement showed an increased in surface area which is responsible for the enhanced photocurrent. The technique can be further extended for increasing the efficiency of si doped hematite system.
5:45 PM - F8.9
Multi-functional Porous Chalcogenide Frameworks for Solar Fuel Production.
Benjamin Yuhas 1 , Yurina Shim 1 , Mercouri Kanatzidis 1 2 Show Abstract
1 Chemistry, Northwestern University, Evanston, Illinois, United States, 2 Materials Science Division, Argonne National Laboratory, Argonne, Illinois, United States
Solar fuel research has recently seen an increased focus on so-called biomimetic systems, which are modeled after biological species capable of light-driven water splitting. Common to all of these systems is the presence of transition metal clusters, which are found principally in nature as the active centers in various biomolecules that are capable of fuel production, such as photosystem II or hydrogenase enzymes. Many researchers have developed analogous inorganic and organometallic molecules that can catalyze hydrogen production from water; however, most of these synthetic analogues are susceptible to catalyst deactivation, primarily by oxygen, which is both the other product of the water splitting reaction as well as a major component of the atmosphere. It is clear, then, that an ideal design motif would have the active catalysts incorporated into a larger framework, as is found in nature, which could serve to protect the catalysts from the adverse effects of oxygen, and may result in significant improvements to long-term catalyst stability. We have recently developed a new class of porous chalcogenide materials, dubbed chalcogels, which may be an ideal supramolecular system capable of producing solar fuels under photochemical conditions. Being based on chalcogenides, these materials are capable of visible light absorption, while possessing surface areas comparable to that of traditional silica-based aerogels. We are able to synthesize chalcogels containing both redox-active [Fe4S4] cluster units as well as light-harvesting photoredox molecules. The [Fe4S4] cluster unit retains its redox properties when bound into the chalcogel framework, and the gels are capable of electrocatalytically reducing a variety of substrates. Additionally, we observe that the photoredox properties of incorporated light-harvesting dye molecules are greatly affected by the presence of the [Fe4S4] cubane clusters in the gels, and that the dye-functionalized gels are capable of producing hydrogen photochemically. With a high degree of synthetic flexibility afforded in our system, the chalcogels can be an ideal platform for the construction of new integrated superstructures relevant to solar fuel production.
F9: Poster Session: Photovoltaics, Batteries, Fuel Cells and Photocatalysts for Renewable Fuels III
Friday AM, April 29, 2011
Salons 7-9 (Marriott)
9:00 PM - F9.1
Enhanced Electrochemical Stability Using a Pt/Graphene-CNT Composite Cathode for Proton Exchange Membrane Fuel Cell.
Daniel Chua 1 , Ting Chen 1 Show Abstract
1 Materials Science & Engineering, National University of Singapore, Singapore Singapore
Pt nanoparticles supported on a Graphene/carbon nanotube composite were syntehsized and studied as a catalyst - gas diffusion layer for oxygen reduction reaction (ORR) in proton exchange membrane fuel cell (PEMFC). Transmission electron microscopy indicated that the carbon nanotubes were intermixed between grphene interlayers and the Pt nanoparticle (3-5nm) are uniformly dispersed on the surface of this composite. Polarization test on our 5cm2 PEMFC showed a good electrochemcial activity of 0.66 A/cm2 at 0.6V. In-situ accelerated degradation test with cyclic voltammetry measurement verfied an enhancement in the electrochemical stability as compared with standard Pt/VXC72R references. We believe the corrosion resistance of the inert graphene/CNT plays a crucial role for the enhanced stability.
9:00 PM - F9.2
Proton Exchange Membranes Equipped with Nanoscale Methanol Diffusion Barrier.
Chunliu Fang 1 2 , David Julius 2 , Liang Hong 2 3 , Jim Yang Lee 1 2 Show Abstract
1 , NUS Graduate School for Integrative Science and Engineering, Singapore Singapore, 2 Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore Singapore, 3 , Institute of Materials Research and Engineering, A* STAR , Singapore Singapore
Methanol has been considered as a renewable alternative energy source of fossil petroleum. The methanol-based power generator, direct methanol fuel cell (DMFC), can be used for portable devices and vehicle applications. However, one of the barriers in the commercialization of DMFCs is the high methanol permeability of current generation of perfluorosulfonated-based proton exchange membranes (PEMs); such as Nafion®. Alternative PEMs with high proton conductivity but lower methanol permeability can be the game-changer. This presentation summarizes our recent findings on the synthesis and properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based proton exchange membranes designed for fuel cell applications.A series of PPO-based semi-interpenetrating network (SIPN) membranes were prepared by interpenetrating the sulfonated PPO moieties in a hydrophobic network of brominated PPO that was in-situ covalent cross-linked by ethylenediamine. The inter-chain entanglement endowed the SIPNs with forcible compatibility in nanoscale and mechanical stability. The thermal transitions and mechanical relaxations of the composite membranes were evaluated by the dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The SIPN construction successfully inhibited methanol permeation through the membranes and improved the membrane dimensional stability by averting excessive swelling until 80 oC. Compared with Nafion® 117, the PPO-based SIPN membranes showed comparable proton conductivity and maximum power density but with a much lower methanol permeability. The PPO-based SIPN membranes have therefore acquired the basic physicochemical properties which are required for DMFC applications.
9:00 PM - F9.3
Sputtered Base Material Electrocatalysts for Oxygen Reduction in Low-temperature Fuel Cells.
Kieran Fahy 1 , Gordon Burstein 1 Show Abstract
1 Materials Science and Metallurgy, University of Cambridge, Cambridge United Kingdom
Non-noble transition metals are known to have catalytic activity to the oxygen reduction reaction but corrode badly in the fuel cell environment. Here we present a form of base-material electrocatalyst which displays considerable activity to the oxygen reduction reaction while remaining quite passive. Direct current magnetron sputtering was used to co-deposit thin-films (ca. 100 nm) of carbon with base transition metals (Ni, Co, Fe) onto carbon paper substrates. Various compositions were tested with metal contents up to 50%. It will be shown that in these films the metals form nanoparticles that are passivated by encapsulating carbon. The electrocatalytic activity of the films was investigated with cyclic voltammetry and cathodic polarisation in a 1.5M sulphuric acid solution at 70°C. The films showed good activity and corrosion resistance at a range of potentials up to 1.23 V(SHE).
9:00 PM - F9.4
Graphene Role as Platinum Support for CO and Formic Acid Electrooxidation.
Shirui Guo 1 , Huseyin Sarialtin 3 , Shaun Alia 2 , Hayri Akin 2 , Yushan Yan 4 , Cengiz Ozkan 3 2 , Mihrimah Ozkan 2 3 1 Show Abstract
1 Chemistry, UC Riverside, Riverside, California, United States, 3 Mechanical Engineering, UC Riverside, Riverside, California, United States, 2 Electrical Engineering, UC Riverside, Riverside, California, United States, 4 Chemical & Environmental Engineering, UC Riverside, Riverside, California, United States
The direct methanol fuel cell (DMFC) is a promising power source for electronic applications due to its high efficiency and compactness. To improve the efficiency, many support materials have been developed. We investigated Uniform graphene nanoflake films as a support for catalytic Pt nanoparticles in direct carbon monooxide and formic acid electro-oxidation. Pt nanoparticles were deposited on the surface of graphene films with chemical reduction method. Chemical functionalization of graphene with ethylenediamine enables Pt nanoparticles mobilize on graphene uniformly. By simply changing the loading amount of Pt precursor, various particle sizes were achieved. The particle size of Pt plays prominent role in fuel cell test. The electrochemically active surface area of different sample are 6.3 (5 wt% Pt/G), 4.1 (20 wt% Pt/G), and 3.0 (50 wt% Pt/G) corresponding to the particle size 3±1nm, 10±2nm, 20±2nm respectively. The results obtained are ascribed to a uniform network made of 2-4 nm Pt monolayer nanopaticles on the surface of graphene flakes. Graphene will play significant role in developing next-generation advanced Pt based fuel cells and their relevant electrodes in the field of energy.
9:00 PM - F9.6
Synthesis of Surface Functionalized Graphene Nanosheets with High Pt-loadings and Their Applications to Methanol Electrooxidation.
Sung Mook Choi 1 , Min Ho Seo 1 , Hyung Ju Kim 1 , Won Bae Kim 1 Show Abstract
1 Materials Science & Engineering, GIST, Gwangju Korea (the Republic of)
Pt-based materials have been recognized as active electrocatalysts in the anodes and cathodes of polymer electrolyte membrane fuel cells (PEMFCs). It is well known that the performance of a fuel cell depends on the size and dispersion of Pt nanoparticles. Furthermore, the Pt must be deposited on support materials with specific properties, such as a large surface area to provide high metal dispersion, a suitable porosity to boost gas flow, a high electrical conductivity to facilitate electron transfer, and a high stability to the electrochemical conditions of fuel cells. Among the suitable carbonaceous support materials, the graphene nanosheets (GNSs) have a high specific surface area (theoretically, ca. 2630 m2/g) and a high electrical conductivity to obtain small and uniformly dispersed Pt nanoparticles.In this study, we have prepared GNS supports through simple synthetic processes that are highly functionalized by surface epoxy, hydroxyl, and carboxyl groups. These processes generally include the chemical oxidation of common graphite-to-graphite oxide (GO) and the subsequent thermal exfoliation of the GO to GNSs. The GNS-supported Pt catalysts, which are prepared by impregnation of a Pt precursor on the functionalized GNSs without employing a surfactant, show very small (under ca. 3 nm, as measured from transmission electron microscopy (TEM)) and uniformly dispersed Pt nanoparticles, even when using high Pt metal depositions of up to 80 wt.% over the GNS supports. The current densities for the methanol electrooxidation with the Pt/GNS catalysts are at least twice as large as those observed with conventional Pt/C catalysts. More importantly, the Pt/GNS catalysts are able to maintain a higher Pt mass activity over a broad range of Pt loading on the working electrode for methanol electrooxidation, ranging from 0.2 to 2.0 mg/cm2. .Reference Choi SM, Seo MH, Kim HJ, and Kim WB. DOI: 10.1016/j.carbon.2010.10.055
9:00 PM - F9.7
Elaboration and Characterization of La4Ni3O10 Cathode Material (SOFC) by Sol-gel Process.
Rene Cienfuegos 1 2 , Leonardo Chavez 1 2 , Sugeheidy Carranza 1 , Laurie Jouanin 3 , Guillaume Marie 4 , Moises Hinojosa 1 2 Show Abstract
1 Materials Science, Facultad de Ingenieria Mecanica y Electrica, San Nicolas de los Garza, Nuevo Leon, Mexico, 2 Advanced Materials, Centro de Innovacion, Investigacion y Desarrollo en Ingeniería y Tecnología , Apodaca, Nuevo León, Mexico, 3 UFR SCIENCES, Universite Paris-Sud 11, Paris, Orsay, France, 4 Department of Chemistry, IUT A de Lille, Villeneuve d’Ascq , Lille, France
The goal in this study was to synthesize a lanthanum - nickel phase (Ruddleden-Poper phases) La4Ni3O10. This mixed conduction material (Material Ionic and Electronic Conduction -MIEC) was prepared using a polymeric route. An easy synthesis method is presented in order to obtain a cheap cathode material, which can be used in Solid Oxide Fuel Cells (SOFC). The polymeric precursors were prepared following the Castillo method. The originality of this work was to optimize the complexation ratio HMTA/ metallic salts from 1 to 6. The obtained powders were characterized by thermal analysis; Differential Scanning Calorimetry (DSC Q10 Instrument TA), Thermogravimetric Analysis (TGA - Q50 Instrument TA-) and X-ray diffraction (Bruker, D8 Advance diffractometer), in order to determine the crystallized phase. Experiments 5 and 6 did not present coagulation but after few days, solution 5 was transformed into a gel. Gels 2 to 5 were heated in order to obtain a solid material. These powders are characterized by thermogravimetric and thermodifferential methods. The powders obtained at 800, 900 and 1000 Celsius were analyzed by X-ray diffraction and it was found that the temperature to get to the La4Ni3O10 phase was 1000 Celsius.