Two key efforts to curb global greenhouse gas emissions involve reducing CO2 into energy-dense liquid fuels and replacing the energy-intensive Haber-Bosch process for nitrogen reduction with an electrochemical alternative. In addition, efforts to electrify long-distance trucking or aviation are limited by the low-energy density of modern lithium-ion chemistries compared to petroleum fuels. Novel materials can address both of these challenges; however, systematic, theoretical evaluations of candidate material systems in-silico are limited to small design spaces and low-fidelity screening that fail to model realistic operating conditions.
The goal of this project is to alter this paradigm by enabling rapid, high-fidelity screening of large numbers of electrochemical functional materials for use in new energy technologies. The team brings together complementary expertise in advanced computing, numerical methods, and materials science. Overall, the team expects to accelerate the overall energy material development and optimization process by 80%.
This project involves software development efforts for accelerated solution of differential and algebraic equations describing the kinetics of the electrochemical systems, integration of these solvers with machine learning approaches, and global optimization over the chemical design space. The high-value candidates will be tested experimentally, validating the entire approach.
We will perform physics-aware machine learning to iteratively guide simulations towards candidate materials. This sequential learning approach will enable an efficient and uncertainty-driven exploration of the high-dimensional design spaces encompassed in this work while allowing for multi-objective optimization of catalyst parameters.
To rapidly generate a large-scale database of reaction intermediate structures, we are developing an automated DFT framework. This will simultaneously accelerate adsorption energy computations while systematically accumulating and manipulating output data in a manner for ease of integration into machine learning models. Moreover, it will facilitate the overall closed-loop sequential learning approach to explore new systems.
Building on the success of Crystal Graph Convolutional Neural Networks in predicting properties of crystalline solids as well as software packages for molecular machine learning such as DeepChem (for which we are developing the official Julia language port), we are developing software to combine these techniques to rapidly and accurately predict energetics of the adsorption processes critical to catalysis of reactions such as nitrogen reduction.
Leveraging the advanced numerical techniques implemented in the Julia programming language, we are developing customized solutions to dramatically speed up the solutions of the challenging stiff differential algebraic equations (DAE’s) that describe the interactions of chemical species on catalytic surfaces.