Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Yuxin Wang Project Name: SOFC Division: XSD Project title: Imaging, Analysis and Simulation of Heterogeneous Functional Materials Associated funding: DoE Other Systems: Primarily workstations at present. Science: The DOE Energy Frontier Research Center (EFRC) on Heterogeneous Functional Materials for Energy Systems (HeteroFoaM Center), led by the University of South Carolina, is a collaboration with scientists at APS, University of Connecticut, Princeton University, University of Utah, the Georgia Institute of Technology, Rochester Institute of Technology, and the University of California-Santa Barbara. The central objective of this EFRC, funded by DOE-SC Office of Basic Energy Sciences, is to build a scientific basis for bridging the gap between making nano-structured materials and understanding how they function in a variety of energy applications (www.science.doe.gov/bes/EFRC/CENTERS/HeteroFoaM/efrc_HeteroFoaM.html). Energy devices such as fuel cells, electrolyzers, combustion and fuel processing devices consist of multiple materials interacting at multiple scales. Establishing a fundamental understanding of the functional behavior of these material systems at multiple length and time scales as the basis for providing a scientific foundation for the conceptual design, simulation and fabrication of nano-structured heterogeneous materials for energy systems is the objective of the EFRC. Central to this effort is the formulation of science-based theory and computational methods for the analysis and simulation of the functional performance of these materials based on their composition, configuration and nano-morphology. Central themes in understanding functional materials in non-equilibrium states involves understanding transport, conversion, transfer of mass, momentum, energy and charge, as well as stability and durability for long-term performance. The present proposal seeks the computational resources required for the reconstruction and analysis of materials imaged using a transmission x-ray microscope at APS beamline 32-ID-C. Structures, elemental and chemistry information obtained will be used to perform quantum chemical and mechanical, and mesoscale (phase-field and lattice Boltzmann) modeling and simulation of the non-equilibrium thermodynamics and diffusion/reaction kinetics at the atomic scale at interfaces in heterogeneous materials, stability of films as function of morphology, and predictive estimation of properties and functional behavior. The methodologies that will be applied include i) quantum-mechanical atomic level simulations to understand how materials behave at interfaces and as function of morphology, dopants, and nano-sized features, ii) mesoscale simulations to incorporate geometrical effects with atomic detail, iii) evaluation of new material properties, and iv) multiscale physics analysis of soli d oxide fuel cells (SOFCs). Project description: This project involves three Universities from the HeteroFoaM EFRC (www.heterofoam.com): Princeton University, University of Connecticut, and University of South Carolina. Project goals and achievements from the previous year are described below: (1) University of South Carolina: Project Title: Rational Design of Sulfur and Carbon Tolerant Anode Materials for Solid Oxide Fuel Cells Project Division: Energy Systems Select PIs and Members: Andreas Heyden, Muhammad Faheem, Suwit Suthirakun, Salai C. Ammal Funding Source: Department of Energy (BES) Award No. DE-SC0001061 (primary) and DE-SC0007167 (secondary) Abstract: The objectives of this project are (1) to develop a doping strategy for mixed ionic/electronic conductivity in perovskite oxides (and to try to understand the physical reasons for the “soup of elements” often found in practical electrodes for solid oxide fuel cells, SOFCs), (2) to understand the fuel oxidation process on the Sr2Fe1.5Mo0.5O6 (001) perovskite oxide surface and the Ni/YSZ (111) interface in the presence and absence of sulfur containing compounds, required for proposing design modifications of SOFCs, and (3) to develop realistic microkinetic models that can be used in, e.g., Lattice Boltzmann simulations to study HeteroFoaMs under operation in a SOFC over “longer” time and length scales. Finally, a limited amount of computer time will also be used to support our efforts to develop computational methodologies for modeling chemical reactions at solid-liquid interfaces relevant for catalytic lignocellulosic biomass conversion processes. New Results: (1) We illustrated that mixed p- and n-doping is an efficient strategy to obtain mixed ionic/electronic conductivity in perovskite oxides such as SrTiO3. Moreover, we have proven that this strategy is valid independent of n-doping site (A- or B-site) in the perovskite structure. Both, La (n-type) and Ga (p-type), and Nb (n-type) and Ga (p-type) doped SrTiO3 exhibit mixed ionic and electronic conductivity in a reducing environment as long as the concentration of p-dopants is significantly below, e.g., half, the concentration of the n-dopant. (2) We understand the rate / performance limiting step in SOFCs based on Sr2Fe1.5Mo0.5O6-δ (SFM) anodes running on H2. After identifying the surface phase of SFM (001) under anodic SOFC conditions with the help of constrained ab initio thermodynamic calculations, we studied the reaction mechanism of the electrochemical H2 oxidation from first principles, and developed a microkinetic model that clearly identified the H2 dissociation step to be rate determining. As a result, adding a transition metal to the SFM surface such as Ni facilitates H2 dissociation and improves the overall cell performance. Indeed, experimental observations from our collaborators confirm this predicted SOFC cell behavior. (3) We understand the reaction mechanism of the electrochemical H2 oxidation at the Ni/YSZ interface. The oxidation mechanism of H2 at the Ni/YSZ interface has been investigated considering the following pathways: (i) H-spillover pathway (H-spillover from Ni to YSZ where water formation occurs), (ii) OH-migration pathway (H-spillover from Ni to YSZ leading to OH species that spillover from YSZ to Ni where water formation occurs), and (iii) O-migration pathway (O-spillover from YSZ to Ni where H2O formation occurs). In all of these pathways H2 adsorbs dissociatively on Ni and reacts with an oxygen atom at the interface which leads to the formation of H2O and a surface vacancy. Analysis of a microkinetic model containing all three pathways led to the following conclusion: If we assume that the cathode reaction is fast, the apparent activation barrier for all three pathways are within the range of reported experimental values (100-135 kJ/mol). However, the highest rate (by t hree orders of magnitude) is predicted for the O-migration pathway. Project Impact: The vision of this research program strikes at the heart of the “Grand Challenges for Basic Energy Sciences” described in the BESAC report. The fundamental objective of this project is to create a scientific basis for the rational design of novel heterogeneous functional materials and their surfaces for applications to SOFCs, supercapacitors, etc. New Capabilities: 1) Implementation and testing of new physical models for electrochemical reactions on perovskite based SOFC anode electrodes. 2) Implementation and testing of new physical models for electrochemical reactions at the three-phase boundary of SOFC anode electrodes. 3) Implementation and testing of new physical models for reactions at solid-liquid interfaces. Publications: 1) S. Suthirakun, S. C. Ammal, G. Xiao, F. Chen, K. Huang, H.-C. zur Loye, A. Heyden, “Obtaining Mixed Ionic/Electronic Conductivity in Perovskite Oxides in a Reducing Environment: A Computational Prediction for Doped SrTiO3,” Solid State Ionics, under review. 2) S. C. Ammal, A. Heyden, “Combined DFT and Microkinetic Modeling Study of Hydrogen Oxidation at the Ni/YSZ Anode of Solid Oxide Fuel Cells,” J. Phys. Chem. Lett., under review. 3) M. Faheem, S. Suthirakun, A. Heyden, “Implicit Solvation Model for Solid Surfaces,” J. Phys. Chem. C, under review. Presentations: 1) “SrTiO3 based Anode Materials for Solid Oxide Fuel Cells: A Computational Attempt to understanding and Improving Performance,” S. Suthirakun, A. Heyden, AIChE Annual Meeting, Minneapolis, MN, October 2011. 2) “Development and Application of a Hybrid QM/MM Method for the Computational Investigation of Reactions at Metal/Water Interfaces,” M. M. Faheem, A. Heyden, AIChE Annual Meeting, Minneapolis, MN, October 2011. 3) “Theoretical Investigation of Heterogeneous Catalysis at the Solid-Liquid Interface for the Conversion of Lignocellulosic Biomass Model Molecules,” A. Heyden, 2011 DOE-BES Catalysis Science PI Meeting, Annapolis, MD, October 2011. 4) “Density Functional Theory Study on the Electronic Structure of n- and p-type doped SrTiO3 as Anode for Solid Oxide Fuel Cells,” S. Suthirakun, S. C. Ammal, A. Heyden, Southeastern Catalysis Society Meeting, Asheville, NC, September 2011. Grants: 1) Department of Energy (BES) Award No. DE-SC0001061 (this is the main grant for the work done at ANL Fusion) 2) Department of Energy (BES) Award No. DE-SC0007167 (selected calculations have been performed at ANL Fusion for this catalysis grant) (2) Princeton University Using the LCRC computing resources, our group is investigating oxygen vacancy formation in solid oxide fuel cell cathode materials. We use accurate first-principles quantum mechanics calculations to provide insight into the fundamental processes that govern oxygen ion transport in these materials. Specifically, fundamentally understanding oxygen transport in mixed ion-electron conducting cathode materials will enable rational design of higher performance devices. We are calculating oxygen migration pathways within LaCoO3 explicitly accounting for quantum mechanical effects related to electron spin. Additionally, thermal effects arising from phonon dispersions may be important in determining accurate oxygen vacancy formation energies. These demanding calculations necessitate substantial computer time, and we have begun using LCRC resources to this end. LCRC support has resulted in a graduate student poster presentation (ECS, Boston, October 2011) and oral presentation (A CS, San Diego, March 2012) at national scientific meetings over the past fiscal year. Conference Presentations A. M. Ritzmann and E. A. Carter, "Ab initio DFT+U investigation of oxygen diffusion in solid oxide fuel cell materials La1-xSrxFeO3 and La1-xSrxCoO3," ACS Spring 2012 National Meeting & Exposition (Presentation Only), San Diego, CA. March 2012. A. M. Ritzmann and E. A. Carter, "First-Principles Quantum Mechanics Assessment of Oxygen Diffusion in La1-XSrXMO3 (M=Fe, Co) Based Materials," 220th ECS Meeting & Electrochemical Energy Summit (Poster Only), Boston, MA. October 2011. (3) University of Connecticut Wilson K. S. Chiu and William M. Harris Department of Mechanical Engineering University of Connecticut [email protected] Microstructural imaging techniques, such as x-ray nanotomography and FIB serial sectioning, are able to provide detailed descriptions of solid-state energy materials at spatial resolutions appropriate for their structure and performance. However, to obtain a quantitative description of these materials, and thus determine their suitability for use in an energy-conversion device, requires a detailed description of the material microstructure. Characterization routines have been implemented on FUSION to analyze structures on the sub-micron scale with respect to such metrics as porosity, tortuosity, specific surface area, and phase contiguity. This analysis has been further extended to consider the relative distribution of different phases within a composite material, such as the Ni-YSZ anode commonly used in solid oxide fuel cell anodes. Furthermore, this characterization has been used as a foundation for more detailed simulations, such as the transport of gases within a dis crete porous structure. The complexity of these structures prevents the possibility of analysis on even a high-end desktop workstation, making the implementation on a machine such as FUSION essential. Publications: L. Zhang, N. Xu, X. Li, S. Wang, K. Huang, W. H. Harris and W. K. S. Chiu, “High CO2 Permeation Flux Enabled by Highly Interconnected Three-Dimensional Ionic Channels in Selective CO2 Separation Membranes,” Energy & Environmental Science, vol. 5, pp. 8310-8317, 2012. G. J. Nelson, K. N. Grew, J. R. Izzo, Jr., J. J. Lombardo, W. M. Harris, A. J. Cocco, A. Faes, A. Hessler-Wyser, J. Van herle, Y. S. Chu, S. Wang, A. V. Virkar and W. K. S. Chiu, “Three-Dimensional Microstructural Changes in the Ni-YSZ Solid Oxide Fuel Cell Anode During Operation,” Acta Materialia, vol. 60, pp. 3491-2500, 2012. J. J. Lombardo, R. Ristau, W. H. Harris and W. K. S. Chiu, “Focused Ion Beam Preparation of Samples for X-ray Nanotomography,” Journal of Synchrotron Radiation, vol. 19, pp. 789-796, 2012. W. M. Harris, G. J. Nelson, A. M. Kiss, J. R. Izzo, Jr., Y. Liu, M. Liu, S. Wang, Y. S. Chu and W. K. S. Chiu, “Nondestructive Volumetric 3-D Chemical Mapping of Nickel-Sulfur Compounds at the Nanoscale,” Nanoscale, vol. 4, pp. 1557-1560, 2012. Conference papers W. H. Harris, G. J. Nelson, J. J. Lombardo, A. P. Cocco, J. R. Izzo, Jr., W. K. S. Chiu, P. Tanasini, J. Van herle, C. Comninellis, J. C. Andrews, Y. Liu, P. Pianetta, and Y. Chu, “Analysis of Solid Oxide Fuel Cell LSM-YSZ Composite Cathodes with Varying Starting Powder Sizes,” Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition, Paper No. IMECE2011-64237, Denver, CO, November 11-17, 2011. Project URL: http://www.science.doe.gov/bes/EFRC/CENTERS/HeteroFoaM/efrc_HeteroFoaM.html Current FY Hours Used: undetermined amount New FY Requested allocation: 800000 Q1: 200000 Q2: 200000 Q3: 200000 Q4: 200000 Justification: Image processing All image processing will be performed using Matlab. We will reconstruct an average of 20 samples per week requiring an average of 48 node hours per calculation (50,000 node hours per year). We will also be performing additional image processing of each sample requiring approximately 50 node hours per calculation (50,000 node hours per year). All calculations will require up to 400 GB of memory. Quantum chemical simulations and Quantum mechanical calculations Our DFT calculations will be performed using the Vienna Ab Initio Simulation Package (VASP) which solves the Kohn-Sham equations subject to periodic boundary conditions using a planewave basis set. We will perform an average of 50 single-point energy calculations each week requiring an average of 48 node hours per calculation (99,840 node hours per year). We will also be performing an average of 3 nudged elastic band calculations each week requiring approximately 1,500 node hours per calculation (234,000 node hours per year). All PEECM calculations will be performed with the Turbomole code (based on Gaussian-type basis sets) using hybrid and double-hybrid density functionals. Transition states required for the calculation of reaction rates will be located with our own highly efficient growing string and improved dimer algorithms. Recent tests on EMSL Chinook confirmed that both VASP and Turbomole scale well up to hundreds of nodes. Overall, we expect that computations required for quantum chemical calculations on the anode side of the SOFC will require approximately 750,000 node-hours per year and 500 GB of memory. This estimate is based on submitting 150 geometry optimizations and 20 transition state searches per year for each the perovskite and double perovskite structures (optimization of a perovskite structure requires on FUSION about 5000 node hours; optimization for a double perovskite structure requires about 12,500 node hours; transition state searches require about 10 times more time than a structure optimization). Phase-field Simulations Our continuum PF simulations will be performed with a parallel MPI code written in-house. While we have not benchmarked this particular code, our experience with similar codes in the past suggests that it should scale well up to 32 or 64 CPUs on the FUSION system. Furthermore, we estimate that a simulation with 1283 (2563) grid points will require 240 (1920) node-hours wall clock time and 100 GB (800GB) of memory. On an annual basis, we expect that our simulations of SOFC anode microstructural evolution phenomena require on the order of 200,000 node hours and 1 TB of memory on the FUSION system, corresponding to 100 high-resolution simulations. Lattice Boltzmann Calculations Our LBM simulation of 3D mass transport and electrochemistry in solid oxide fuel cells scales well up to 64 CPU on a local SGI Altix 850 system. For the FUSION system, we estimate that a single case using low resolution 813 lattice will require 350 node-hours wall-clock time and 100 GB memory on the FUSION system. A high resolution 6743 lattice will enable us to simulate realistic physical domain sizes and lead to better accuracy of the model predictions, but each case will require 22,400 node-hours wall-clock time and 1 TB memory on the FUSION system. Our annual estimated EFRC project needs on the FUSION system are 300,000 node hours: two low resolution lattice cases per week (36,400 node-hours wall-clock time per year), and one high resolution lattice case per month (268,800 node-hours wall-clock time per year). Summary of Computing Resource with Software, Node Hours, and Storage GB needs: Image Processing: Matlab, 50,000 node-hour, 400 GB Quantum chemical simulations: Turbomole, 140,000, 1,000 GB Quantum mechanical calculations: VASP, 358,800 node-hour, 1,500 GB Phase-field simulations: Intel C++ Compiler, 200,000 node-hour, 1000 GB Lattice Boltzmann calculations Intel Fortran Compiler: 50,000 node-hour, 1,500 GB Total: 798,800 node-hour, 5,400 GB Thank You, The LCRC Accounts System