First Principles Theory and Modeling of Interfacial Processes for Environment-Friendly Materials
EMSL Project ID
47584
Abstract
A fundamental knowledge of the chemical and physical properties at gas-solid or liquid-solid interfaces is essential for the design and discovery of breakthrough materials. Computational strategies using high performance computing provide the opportunity to design surfaces and interfaces with desired functionalities. This requires both an understanding of the processes that are occurring at the interfaces as well as relating desired properties to key calculated parameters such as reaction energies and barriers, which can be used in screening many potential candidates. This proposal is focused on the use of computations to both understand structure-function relationships as well as use of this insight to help design new materials for processes involving various types of catalysis and energy storage. The computational studies will be based on state-of-the-art electronic structure methods including density functional theory, a powerful tool for understanding and design of new catalysts. The proposed computational studies involve collaboration with world-class experimentalists at the Pacific Northwest National Laboratory and Argonne National Laboratory. The computations will be focused on three interrelated areas: (1) catalysis by subnanometer clusters, (2) photocatalysis on TiO2 surfaces, and (3) modeling of solid-liquid interfaces. New catalysts are needed for making and breaking specific bonds for energy efficient and environmentally friendly catalysts. Recent studies have shown that supported subnanometer clusters exhibit novel catalytic properties for breaking C-H and O-H bonds. We will carry out systematic studies to explore the unusual catalytic properties of these clusters and to determine how they might be tailored to make and break specific bonds. These computations will play a key role in the design and discovery of environmentally friendly catalysts for industrial processes. Electrocatalysis provides a low-temperature, energy efficient alternative to heterogeneous catalysis that has potential uses for chemical transformations as well as the development of alternative energy sources. We will investigate the use of subnanometer clusters for carbon dioxide electroreduction, wherein CO2 is electrochemically reduced to CO and hydrogenated products in acidic solution. This reaction has the potential to both produce useful chemicals from an essentially limitless feedstock and reduce atmospheric greenhouse gas loadings. Efficient utilization of solar energy through photocatalysis would be a significant step towards easing current energy demands. TiO2 is a prototypical photocatalyst used for organic pollutant degradation and also for water splitting, H2 being an important fuel source. Despite the importance of TiO2, there are many fundamental issues that are not well understood, such as how photoexcited holes and electrons interact with surface adsorbates and lead to their catalytic decomposition. Molecular modeling methods provide an excellent way to study surface reactions and provide insights into the intermediates and reaction pathways. Finally, we will use computations to model the solid-electrolyte interfaces involved in energy storage systems as well as catalysis. In lithium ion batteries the SEI plays a key role in the performance and safety of li-ion batteries and have become one of the most important energy storage devices for portable electronics, electric and plug-in hybrid vehicles, owing to their high energy density and design flexibility. Computations will be used to study the structure and properties of important SEI components and how they are formed from electrolytes.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2012-10-01
End Date
2014-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members