Bulletin of the American Physical Society
APS March Meeting 2013
Volume 58, Number 1
Monday–Friday, March 18–22, 2013; Baltimore, Maryland
Session T38: Renewable Fuels |
Hide Abstracts |
Sponsoring Units: DMP GERA FIAP/DCOMP Chair: Peter Zapol, Argonne National Laboratory Room: 347 |
Thursday, March 21, 2013 8:00AM - 8:12AM |
T38.00001: First Principles Study for Proton Transport and Diffusion Behavior in Hydrous Hexagonal WO3 Chi-Ping Liu, Fei Zhou, Vidvuds Ozolins Proton transport is of great importance in biological species and energy storage and conversion systems. Previous studies have shown fast proton conduction in liquids and polymers but seldom in inorganic materials. In this work, first principles density functional theory (DFT) reveals that the formation of hydronium and water chains inside the hexagonal channels plays the key roles for the anomalously fast proton transport, by following modified Grotthuss mechanism. Our DFT study shows the detailed microscopic proton diffusion mechanism along the channel in hydrous WO3 with 50{\%} water composition, which is proper for water chain formation. The water chain in the channel serves as a possible diffusion media for hydronium (H3O$+)$. With the continuous formation and cleavage of hydrogen bonds in the channel, the hydronium diffuses by hydrogen bonds exchange between water molecules. This mechanism is very similar with Grotthuss relay mechanism for proton transport in liquid. The possible proton diffusion were studied for hydronium is either far away from the water chain bond defect or next to H2O defect at the end of water chain. The diffusion barriers for both conditions are around 150 meV to 200 meV, and water defects reorganization in the chain is the rate-limited step for proton diffusion. These small diffusion barriers could explain the fast 1-D proton transport in hydrous WO3 channel. Further studies about fast proton transport in other inorganic materials could be an important topic in not only biochemistry but also clean energy applications like fuel cell applications. [Preview Abstract] |
Thursday, March 21, 2013 8:12AM - 8:24AM |
T38.00002: Density functional theory study of triple phase boundaries of solid oxide fuel cells Angelo Bongiorno, Massimo Malagoli In this work, we present a modeling study of triple phase boundary regions of solid oxide fuel cells (SOFCs) based on a density functional theory approach. In particular, we consider the following solid oxide electrolytes, yttrium-doped barium zirconate (BZY) and yttrium-doped barium cerate (BCY), and the following metallic catalysts, palladium, nickel, and copper. Thus, we use density functional theory calculations to construct the energy landscape for a hydrogen species crossing triple phase boundaries based on the materials above. This study focuses, in particular, on the role played by the metal-oxide interface in controlling the proton transfer from the catalyst to the electrolyte component of triple phase boundaries. Our results are discussed in light of the hydrogen spilling process occurring at triple phase boundaries based on nickel and yttria-stabilized zirconia. [Preview Abstract] |
Thursday, March 21, 2013 8:24AM - 8:36AM |
T38.00003: Electronic and Optical Properties of Tungsten Oxide and Copper Tungstate for Water Oxidation Yuan Ping, Yan Li, James C. Hill, Kyoung-Shin Choi, Giulia Galli We report first principles calculations of the electronic and optical properties of tungsten oxide clathrates [1,2] and copper tungstate solid solutions, which are considered to be promising materials for oxygen evolution in photo-electrochemical cells. In particular, we considered WO3 intercalated with rare gas atoms and small closed shell molecules, and CuW xMo1-xO4 solid solutions. Although relatively efficient photoanode materials, WO3 and CuWO4 are poor light absorbers, due to their band gap above 2.3 eV. In the case of WO3, we found that intercalation with Xe, N2 and CO may lead to a substantial decrease of the optical gap, mostly due to structural modifications of the oxide lattice. Our results for dinitrogen provided an interpretation of recent experiments [1]. In the case of CuWO4, we observed a 0.5-0.6 eV decrease of the gap when doping with Mo (50\% to 75\% concentration), in agreement with recent measurements. The gap decrease originates from a downward shift of the conduction band minimum. A detailed discussion of how intercalation and doping affect the electronic properties of tungsten oxide and copper tungstates will be presented. [1] Q. Mi et al, J. Am. Chem. Soc. 2012, DOI: 10.1021/ja3067622 [2] Y. Ping et al, Chem. Mat. 2012, DOI:10.1021/cm3032225 [Preview Abstract] |
Thursday, March 21, 2013 8:36AM - 8:48AM |
T38.00004: Surface Hydroxyl Groups of Anodized TiO2 Nanotube for More Efficient Photoenergy Conversion Chiung-Yuan Lin, Jing-Neng Yao Experimentalists can apply a hydrothermal crystallization method to the anodized TiO$_{\mathrm{2}}$ nanotube-array. Structural transformation of the nanotubes is easily induced if the tubes are treated by hydrothermal solutions of different pH levels. Such transformation under the treatment of basic solutions, if not damaging the nanotubes, will in turn strongly enhance the anchoring of the carboxyls to the tube surface, and consequently improve the performance of the dye-sensitized solar cells with the TiO2 nanotubes being the photoelectrodes. In this work, we perform density-functional calculations of such nanotubes with different H$^{\mathrm{+}}$ and OH$^{\mathrm{-}}$ attaching to the tube surface. The results provide a great deal of additional details of the tube morphology that is not accessible by the experiments, and reproduce the stability observed experimentally under the attachment of different functional groups. [Preview Abstract] |
Thursday, March 21, 2013 8:48AM - 9:00AM |
T38.00005: Theoretical and Experimental Co {\it K}-edge XAS of Layered Cobalt Oxides Catalysts Michal Bajdich, Daniel Friebel, Boon S. Yeo, Mary Louie, Daniel J. Miller, Hernan S. Casalongue, Felix Mbuga, Tsu-Chien Weng, Dennis Nordlund, Dimosthenes Sokaras, Alexis T. Bell, Anders Nilsson The efficient water oxidation for fuel production from sunlight, with the use of earth-abundant catalysts, is of high importance to photo-fuel cell research. Recent experimental investigations of Co-oxide based catalysts under active conditions of water oxidation show evidence for layered cobalt-oxide structures with possible cation intercalation from electrolyte. To gain insight into our experimentally measured Co {\it K}-edge x-ray absorption spectra of Co-oxide anodes compared to spectra of powder standards such as CoOOH, Co(OH)$_2$ and Co$_3$3O$_4$, we perform theoretical investigations of these spectra. We employ density functional theory plus U (DFT+U) calculations of {\it K}-edge x-ray absorption spectra using core-hole approach which has been shown to accurately capture the pre-edge features of similar $\alpha$-LiCoO$_2$ [1]. We consider $\beta$-CoOOH, $\alpha$-KCoO$_2$, $\gamma$-K$_{0.5}$CoO$_2$ structures as possible candidates. [Preview Abstract] |
Thursday, March 21, 2013 9:00AM - 9:12AM |
T38.00006: Accelerated discovery of materials for solar fuel cells at JCAP Slobodan Mitrovic, Earl Cornell, John Gregoire, Joel Haber, Kevin Kan, Sean Lin, Xiaonao Liu, Martin Marcin, Edward Soedarmadji, Santosh Suram, Chengxiang Xiang, Jian Jin High-Throughput Experimentation group at the Joint Center for Artificial Photosynthesis has a formidable mission: provide accelerated discovery of new photon absorbers and heterogeneous (photo)catalysts for solar fuel cells at the rate far beyond anything attempted in material science to date. The HTE pipeline includes material synthesis, screening and characterization. Within the first year of operations, our fabrication capabilities have risen to 100,000 samples per day using combinatorial inkjet-printing. Such high rate of sample production is setting daunting requirements on screening methods. We are developing and testing methods for fast bandgap measurements, using colorimetry and uv-vis spectroscopy. Material thickness and roughness is determined by confocal chromatic spectroscopy. Catalytic activity is screen through a massively parallel bubble screen and a fast scanning droplet (photo)electrochemical cell. Concurrently, we are developing protocols for high-throughput determination of phase and structure (XRD), surface composition and chemistry (XPS), surface area measurement, etc. on the characterization side of the pipeline. [Preview Abstract] |
Thursday, March 21, 2013 9:12AM - 9:24AM |
T38.00007: First-Principles Study of Photochemical Activation of CO$_2$ by Ti-based Oxides Haiying He, Peter Zapol, Larry Curtiss The photochemical conversion of CO$_2$ and H$_2$O into energy-bearing hydrocarbon fuels provides an attractive way of mitigating the green-house gas CO$_2$ and utilizing solar energy as a sustainable energy source. However, due to the high reduction potential and chemical inertness of CO$_2$ molecules, the conversion rate of CO$_2$ is impractically low. The activation of CO$_2$ is critical in facilitating further reactions. By carrying out first-principles calculations of reaction pathways from CO$_2$ to CO$_2^{-}$ anions on Ti-based oxides including zeolites in the presence of photoexcited electrons, we have studied the initial step of CO$_2$ activation via 1e transfer. It is shown that the CO$_2$ reactivity of these surfaces strongly depends on the crystal structure, surface orientation, and presence of defects. This opens a new dimension in surface structure modification to enhance the CO$_2$ adsorption and reduction on semiconductor surfaces. [Preview Abstract] |
Thursday, March 21, 2013 9:24AM - 9:36AM |
T38.00008: Computational Modeling of Photocatalysts for CO2 Conversion Applications De Nyago Tafen, Christopher Matranga To make photocatalytic conversion approaches efficient, economically practical, and industrially scalable, catalysts capable of utilizing visible and near infrared photons need to be developed. Recently, a series of CdSe and PbS quantum dot-sensitized TiO$_{2}$ heterostructures have been synthesized, characterized, and tested for reduction of CO$_{2}$ under visible light [1]. Following these experiments, we use density functional theory to model these heterostructured catalysts and investigate their CO$_{2}$ catalytic activity. In particular, we study the nature of the heterostructure interface, charge transport/electron transfer, active sites and the electronic structures of these materials. The results will be presented and compared to experiments. The improvement of our understanding of the properties of these materials will aid not only the development of more robust, visible light active photocatalysts for carbon management applications, but also the development of quantum dot-sensitized semiconductor solar cells with high efficiencies in solar-to-electrical energy conversion.\\[4pt] [1] C. Wang, R. L. Thompson, J. Baltrus, and C. Matranga. Phys. Chem. Lett. 2010, 1, 48; C. Wang, R. L. Thompson, P. Ohodnicki, J. Baltrus, and C. Matranga. J. Mater. Chem. 2011, 21, 13452. [Preview Abstract] |
Thursday, March 21, 2013 9:36AM - 9:48AM |
T38.00009: Predicting a new quaternary metal oxide and the study of its structural, electronic, and optical properties by density functional theory Pranab Sarker, Muhammad N. Huda Our recent theoretical and computational research work of a new quaternary metal oxide CuBiW$_{2}$O$_{8}$ and its electronic properties will be presented. Our density functional theory (DFT) total energy calculation using mineral database of relevant oxides determines the crystal structure of CuBiW$_{2}$O$_{8}$ to be a triclinic structure, which agrees with the experimental result. CuBiW$_{2}$O$_{8}$ has a calculated band gap of 1.43 eV suitable for solar-to-hydrogen conversion technology through photoelectrochemical (PEC) approach. The band structure calculation reveals that CuBiW$_{2}$O$_{8}$ possesses indirect band gap. In addition to this, partial DOS plot calculation demonstrates how Cu 3d plays a major role in band gap reduction and why favorable p-d electron transition is likely although band edges are mostly dominated by d orbital electrons. Finally, we find this material is optically anisotropic. [Preview Abstract] |
Thursday, March 21, 2013 9:48AM - 10:00AM |
T38.00010: Comparison Between Crystalline and Amorphous Surfaces of Transition Metal Oxide Water Oxidation Catalysts: a Theoretical Perspective Jonathan H. Skone, Giulia Galli Amorphous films of transition-metal oxide water oxidation catalysts (WOCs) often show an enhanced catalytic activity compared to their crystalline counterparts [1-4]. In particular, in the case of cobalt-oxide based WOCs the observed similarity in their electrochemical properties and catalytic activity, under oxidative conditions, has been correlated with the formation of similar amorphous surface morphologies, suggesting the presence of a common, catalytically active amorphous structural motif [3,4]. We present ab initio calculations of cobalt oxide based material surfaces and we compare the electronic properties of crystalline and amorphous surfaces, with the aim of identifying differences related to their different catalytic activity.\\[4pt] [1] Blakemore, J. D., Schley, N. D., Kushner-Lenhoff, M. N., Winter, A. M., D'Souza, F., Crabtree, R. H., and Brudvig, G. W. Inorg. Chem. 51, 7749 (2012); [2] Tsuji, E., Imanishi, A., Fukui, K.-I. and Nakato, Y. Electrochimica Acta 56, 2009 (2011); [3] Jia, H., Stark, J., Zhou, L. Q., Ling, C., Takeshi, S., and Markin, Z. RSC Advances 2, 10874 (2012); [4] Lee, S. W., Carlton, C., Risch, M., Surendranath, Y., Chen, S., Furutsuki, S., Yamada, A., Nocera, D. G., and Shao-Horn, Y. J. Am. Chem. Soc. 134, 16959 (2012). [Preview Abstract] |
Thursday, March 21, 2013 10:00AM - 10:12AM |
T38.00011: Ab initio study on microscopic properties of III-V/water interfaces for photoelectrochemical hydrogen production Brandon Wood, Woon Ih Choi, Eric Schwegler, Tadashi Ogitsu Photoelectrodes made of III-V semiconductors are known to exhibit very high solar-to-hydrogen conversion efficiency (from solar energy to chemical energy as H$_{\mathrm{2}}$ bond); however, photocorrosion of the electrode in electrolyte solution remains an issue. Based on ab-initio molecular dynamics simulations, we study the structure, stability, and chemical activity of GaP/InP(001) semiconductor electrodes in contact with water. We will show how surface oxygen and hydroxyl change the electronic and chemical properties of water at the interface, leading to the formation of a strong hydrogen-bond network where fast surface hydrogen transport seems to be realized. Implications from our findings will be discussed in detail at the presentation. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52- 07NA27344. [Preview Abstract] |
Thursday, March 21, 2013 10:12AM - 10:24AM |
T38.00012: Decarboxylation of furfural on Pd(111): Ab initio molecular dynamics simulations Wenhua Xue, Hongli Dang, Darwin Shields, Yingdi Liu, Friederike Jentoft, Daniel Resasco, Sanwu Wang Furfural conversion over metal catalysts plays an important role in the studies of biomass-derived feedstocks. We report \textit{ab initio} molecular dynamics simulations for the decarboxylation process of furfural on the palladium surface at finite temperatures. We observed and analyzed the atomic-scale dynamics of furfural on the Pd(111) surface and the fluctuations of the bondlengths between the atoms in furfural. We found that the dominant bonding structure is the parallel structure in which the furfural plane, while slightly distorted, is parallel to the Pd surface. Analysis of the bondlength fluctuations indicates that the C-H bond is the aldehyde group of a furfural molecule is likely to be broken first, while the C$=$O bond has a tendency to be isolated as CO. Our results show that the reaction of decarbonylation dominates, consistent with the experimental measurements. [Preview Abstract] |
Thursday, March 21, 2013 10:24AM - 10:36AM |
T38.00013: Ab initio study on the dynamics of furfural at the liquid-solid interfaces Hongli Dang, Wenhua Xue, Darwin Shields, Yingdi Liu, Friederike Jentoft, Daniel Resasco, Sanwu Wang Catalytic biomass conversion sometimes occurs at the liquid-solid interfaces. We report \textit{ab initio} molecular dynamics simulations at finite temperatures for the catalytic reactions involving furfural at the water-Pd and water-Cu interfaces. We found that, during the dynamic process, the furan ring of furfural prefers to be parallel to the Pd surface and the aldehyde group tends to be away from the Pd surface. On the other hand, at the water-Cu(111) interface, furfural prefers to be tilted to the Cu surface while the aldehyde group is bonded to the surface. In both cases, interaction of liquid water and furfural is identified. The difference of dynamic process of furfural at the two interfaces suggests different catalytic reaction mechanisms for the conversion of furfural, consistent with the experimental investigations. [Preview Abstract] |
Thursday, March 21, 2013 10:36AM - 10:48AM |
T38.00014: Analysis of Enzymatic Degradation of Cellulose Microfibrils using Quantitative Surface Plasmon Resonance Imaging Kyle Reiter, Adam Raegen, Scott Allen, Amanda Quirk, Anthony Clarke, Jacek Lipkowski, John Dutcher Cellulose is the largest component of biomass on Earth and, as a result, is a significant potential energy source. The production of cellulosic ethanol as a fuel source requires conversion of cellulose fibers into fermentable sugars. Increasing our understanding of the action of cellulose enzymes (cellulases) on cellulose microfibrils is an important step in developing more efficient industrial processes for the production of cellulosic ethanol. We have used a custom designed Surface Plasmon Resonance imaging (SPRi) device to study the action of cellulases from the \textit{Hypocrea jecorina }secretome on bacterial cellulose microfibrils. This has allowed us to determine the rates of action and extent of degradation of cellulose microfibrils on exposure to both individual cellulases and combinations of different classes of cellulases, which has allowed us to investigate synergistic interactions between the cellulases. [Preview Abstract] |
Thursday, March 21, 2013 10:48AM - 11:00AM |
T38.00015: Advances in Surface Plasmon Resonance Imaging enable quantitative measurement of laterally heterogeneous coatings of nanoscale thickness Adam Raegen, Kyle Reiter, Anthony Clarke, Jacek Lipkowski, John Dutcher The Surface Plasmon Resonance (SPR) phenomenon is routinely exploited to qualitatively probe changes to the optical properties of nanoscale coatings on thin metallic surfaces, for use in probes and sensors. Unfortunately, extracting truly quantitative information is usually limited to a select few cases -- uniform absorption/desorption of small biomolecules and films, in which a continuous ``slab'' model is a good approximation. We present advancements in the SPR technique that expand the number of cases for which the technique can provide meaningful results. Use of a custom, angle-scanning SPR imaging system, together with a refined data analysis method, allow for quantitative kinetic measurements of laterally heterogeneous systems. We first demonstrate the directionally heterogeneous nature of the SPR phenomenon using a directionally ordered sample, then show how this allows for the calculation of the average coverage of a heterogeneous sample. Finally, the degradation of cellulose microfibrils and bundles of microfibrils due to the action of cellulolytic enzymes will be presented as an excellent example of the capabilities of the SPR imaging system. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700