Collaborative Proposals #1264104 - Susan B. Sinnott #1263951 - Michael J. Janik
Scientific Merit: As traditional fossil fuel sources of energy are depleted, new energy conversion and chemical energy storage approaches will be needed to supply energy for both portable and stationary applications. Fuel cells offer efficient conversion of chemical to electrical energy. Electrolysis applications reverse this process and store electricity from renewable sources, such as the wind or sun, in chemical form for later use. The efficiency of converting energy between chemical and electrical forms is dictated by atomistic processes that occur at device electrodes. These processes are difficult to probe with conventional experiments. The characterization of these processes is enabled using atomic and quantum level computational methods.
There are two major limitations in current modeling approaches for evaluating reactivity of electrode surfaces: the inability to estimate rates for electron transfer reactions and the lack of atomistic force fields that can describe chemical reactions and charge transfer, yet retain the thickness required to capture relevant interfacial phenomena. Professors Michael Janik and Janna Maranas of Pennsylvania State University and Susan Sinnott of the University of Florida have received an award from the National Science Foundation Catalysis & Biocatalysis Program to tackle these limitations. The first limitation will be addressed through the development of a transferable method for electron transfer rate constants using methods based on quantum mechanics. This method will be applied and validated versus experimental data for the carbon dioxide reduction reaction (of relevance for converting electrical energy and waste carbon dioxide into a chemical fuel) and the oxygen reduction reaction (of relevance in fuel cells). The method will be further applied, in collaboration with experiment, to evaluate the reaction mechanism in the electrocatalytic synthesis of high value chemicals from bio-derived feedstock. The second limitation will be addressed through a reactive molecular force field with variable partial charges for both electrode and solvent. Charge optimized many-body reactive potentials will be developed for copper and platinum electrodes in contact with alkali hydroxide electrolytes. Molecular dynamics calculations will evaluate electrochemical interface, including solvent structure and charge distribution. These multiscale atomistic modeling tools enable definitive identification of electrochemical reaction mechanisms. They will be applied to three specific electrocatalytic applications to evaluate a series of reaction specific hypotheses.
Broader Impacts: The broader impacts of this work secure a clean energy future in which renewable energy and chemical energy storage work together to provide an efficient, practical approach to sustainable energy. This project develops a joint quantum chemistry and reactive molecular dynamics framework to model electrochemical interfaces, facilitating rational design of materials for improved batteries, fuel cells, and grid-level electrochemical energy storage. With this in mind, educational activities are designed to motivate students to pursue careers in energy related fields. Graduate students will benefit from an inter-disciplinary research project at two universities, and become skilled in multiple computer simulation methods. Portions of the proposed work will be packaged as undergraduate projects at both Penn State and the University of Florida, including underrepresented groups through the Penn State Minority Undergraduate Research Experience and Women in Science and Engineering Research programs. Research opportunities will be provided to high school students through the U. of Florida. The developed computer simulation methods will be broadly distributed to the computational community, allowing others to apply the techniques developed to electrochemical problems outside the scope of this proposal.
