Executive Summary : | Ammonia, NH3, is one of the key molecules in Earth's ecosystem; as well as it is an important industrial raw material for the production of fertilizers, refrigerants, and other chemicals. Although till the day main consumer (~80% of world production) of NH3 is the fertilizer industry. As this simple molecule holds 3 H atoms (17.65 wt% hydrogen content) and possesses a high energy density (4.32 kWh/L at −33.3 °C), hence could be employed as a potential energy vector - to solve one of the world's greatest concerns, the energy crisis. Especially it could be a carrier for hydrogen for easy transportation and storage of the fuel and we can crack it back to hydrogen. In the past couple of years, global research communities, as well as industries, also refocused on the idea of "NH3 as an alternative fuel of the future". But the “green NH3” i.e. the environmentally benign NH3 synthesis is the main concern. At present, the conventional, high temperature-high pressure Haber Bosch process (HB) has an enormous carbon footprint, as it emits ~3% of global carbon dioxide and consumes 2% of the world’s total energy production. Electrochemical synthesis route could be a vital choice for “green NH3” synthesis, where nitrogen reduction reaction (NRR) is one of the hardest reactions to carry out due to the strong N-N triple bond coupled with poor nitrogen adsorption on many catalysts. Further, the facile kinetics of competing reactions such as hydrogen evolution reaction (HER) has further reduced the suitability of many catalysts for this reaction. The recent surge in interest in the electrochemical synthesis of NH3 has highlighted the inadequacy of NRR catalysts. This project will address this challenging problem by laying the scientific foundation for the development of a new class of highly efficient NRR mono and di atomic catalysts on 2D monolayer substrates. 2D substrates is well- known for its high surface area and easy tunability of electronic properties. 1st part of this project will employ high-throughput screening to identify possible catalysts for electrochemical direct NRR in atmospheric conditions. First principle based atomistic simulations will identify the potential determine and rate determine step of NRR, together with the stability of predicted catalysts to address the catalyst decomposition under the reaction conditions, which is a crucial bottleneck of electrochemical NH3 synthesis. The 2nd part of the project will study key relationships between substrate structure twistronics (rotated 2D layers), and NRR electrocatalysts activity. This part will significantly add a new direction to the theoretical prediction of NRR catalytic activity. In general, the proposed research presents a transformative novel catalyst design technique offering control of discrete reaction steps of NRR through tuning the binding characteristics of the surface species and rotation of 2D substrates, in order to improve the activity and selectivity of electrocatalysts. |