Executive Summary : | The nitrogen fertilizers, like ammonia and urea, are one of the most important synthetic chemicals essential for sustaining the food supply to the ever-growing global population. Ammonia is also a carbon-free energy carrier and energy dense renewable liquid fuel that generates only N2 and water on burning. Today, Haber-Bosch (HB) process is the most common industrial process of ammonia production, but it is energy intensive, requires harsh reaction conditions (550 °C & 350 bar), and emit large CO2 for deriving H2 via steam methane reforming. Urea is commercially produced by reacting CO2 with ammonia also at high pressure and high temperature. Therefore, an alternative, less energy intensive and environment-friendly strategy for the synthesis of ammonia and urea under ambient condition is highly necessary to achieve carbon-neutrality. Amongst various methods, due to advantages in terms of atom and energy economies, electrocatalytic CO2 reduction (ECR) and nitrogen reduction reaction (ENRR) using renewable electricity has evolved as a promising way to tackle this issue. Particularly, urea synthesis under ambient conditions via direct electrocatalytic C-N bond coupling between CO2 and N2 molecules can be a promising alternative to harsh industrial processes. However, only a few such attempts were made to couple N2 and CO2 in water to synthesize urea under ambient conditions, albeit with very low catalytic activity and selectivity. The main challenges are weak chemisorption of inert CO2/N2 on the catalyst’s surfaces, high overpotential requirement for the dissociation of stable C=O bond and N≡N bond, and competitive hydrogen evolution reaction. These challenges can be addressed by designing an efficient and selective ENRR and ECR electro-catalysts to enhance the adsorption and activation of N2 and CO2 to promote C-N coupling reaction for urea synthesis. Aiming at this challenging field, we propose to design, develop, optimize, and implement the use of an earth abundant metal-based electrocatalysts for electrochemical synthesis of nitrogen fertilizers, with a primary focus on ammonia and urea. Specifically, we aim to evaluate the defect-rich earth abundant transition metal nitrides (TMNs) and oxy-nitrides (TMONs) derived from metal organic frameworks and MXenes with improved activity and stability. We aim to understand the catalytic reaction mechanism and to unveil catalyst’s active-sites towards ENRR and electrochemical C-N coupling reaction through extensive physico-chemical and electrochemical measurements, which is critical for further development and optimization of ENRR electrocatalysts. The successful project execution would lead to the development of catalysts for the synthesis of nitrogen fertilizers under ambient conditions that not only will provide alternate way to energy intensive Haber-Bosch process but also will help towards reducing the carbon footprint from agricultural activities. |