Electrochemical Synthesis of Ammonia Using Molybdenum-Based Catalyst

Introduction Today, ammonia is one of the most important chemical products, which is applicable in the production of fertilizer, explosive materials, and refrigerant (1). The traditional ammonia synthesis method is the Haber-Bosch process, in which nitrogen and hydrogen gases react on enriched iron catalyst at high pressure and temperature. Moreover, the final hydrogen conversion is low due to thermodynamic restrictions (2). Electrochemical synthesis of ammonia is a promising process to overcome the limitation of the conventional catalytic rectors such as the low conversion, severe environmental pollution, and high energy consumption (3). Several metals such as platinum (Pt), iridium (Ir), and iron (Fe) based catalysts have been tested for ammonia production through the electrochemical process (4). Apart from catalyst, different kinds of electrolyte including liquid electrolyte, molten salts, composite membrane, and solid state electrolyte have been tested for ammonia synthesis. Liquid electrolytes are effectively active at lower temperature with respect to other electrolytes (5). Although several studies have been performed on electrochemical synthesis of ammonia, most of them represent very low ammonia production rate even in high pressure or high temperature conditions. In this study, liquid electrolyte containing molybdenum (Mo) based catalyst will be investigated to facilitate electrochemical synthesis of ammonia at atmospheric pressure and ambient temperature. The effect of catalyst concentration on the process yield will be studied to develop an appropriate catalytic media for the cathodic reaction of electrochemical reduction of nitrogen to ammonia. Pure hydrogen and nitrogen will be used in the process and product analysis will be performed using ammonia ion-selective electrode (ISE) to determine the concentration of ammonia. References 1. M. Karolewska, E. Truszkiewicz, B. Mierzwa, L. Kępiński and W. Raróg-Pilecka, Applied Catalysis A: General , 445 , 280 (2012). 2. W. Wang, X. Cao, W. Gao, F. Zhang, H. Wang and G. Ma, Journal of Membrane Science , 360 , 397 (2010). 3. I. A. Amar, R. Lan, C. T. Petit and S. Tao, Journal of solid state electrochemistry , 15 , 1845 (2011). 4. M. Hasnat, M. Karim and M. Machida, Catalysis Communications , 10 , 1975 (2009). 5. S. Giddey, S. Badwal and A. Kulkarni, International Journal of Hydrogen Energy , 38 , 14576 (2013).