First-principles study of nitric oxide reduction reactions for ammonia electrochemical synthesis

• Main Author: Foo, Yong Chean
• Other Authors: Li Shuzhou
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Materials::Energy materials; Engineering::Materials::Testing of materials
• Online Access: https://hdl.handle.net/10356/159187
• Institution: Nanyang Technological University

As one of the most important gases used in our human history and the ecology of our planet, ammonia has played a key role as the chemical feedstock in the synthesis of reactive nitrogen compounds between nitrogen-fixing rhizobia and plants. With more upcoming clean renewable energy technology aiming to make use of its high volumetric energy density for its potential for fuel and cheap grid-level scale energy storage solution, demand for NH3 has been at its highest yet. Therefore, alternatives to ammonia production have been highly sought after to replace the ever energy intensive and huge quantities of greenhouse gas that is produced by Haber-Bosch process every day. Electrochemical synthesis of ammonia which has shown the most promise out of the 3 clean alternatives to Haber-Bosch process represents an attractive prospect for sustainable agriculture. With numerous progresses being made recently for nitrogen reduction reaction (NRR), it is still far from practice, owning to the chemical inertness of nitrogen molecule. Hence, with nitric oxide reduction reaction (NORR) potentially being an option to overcome the difficulties faced in NRR, in this simulation, we would like to explore and trial the possibility of NORR for use in electrochemical synthesis of ammonia by providing a more in-depth and comprehensive analysis. As such, in this project, we would like to present insights from density functional theory (DFT) simulations and calculations among a group of metals, namely, Ag, Au, Cu, Ni, Pd and Pt on facet (111) as it is the most stable site and facet (110) as it is a common stepped edge that can be found on the nanoparticle. With these 2 facets, we will be able to provide a realistic and accurate first step analysis of the reaction to describes the prospect of NORR in ammonia electrochemical synthesis. Hydrogen evolution reaction (HER) will be considered as well during our calculation since it is the major competition reaction during reduction of nitrogen species.