Electrocatalytic Oxidation of Ammonia for Energy Conversion and Storage (Final Report)
Ammonia is one of the most promising candidates to be a major renewable fuel. Ammonia is synthesized from H 2 and N 2 , which is the most abundant gas in the Earth’s atmosphere, using the Haber-Bosch (HB) process in the largest scale production of a chemical commodity. Using H 2 generated from renewable resources would result in a scalable, carbon-free, high energy density liquid fuel. The HB reaction is almost thermoneutral, which means hydrogen’s intrinsic energy is largely retained in the ammonia product, making NH 3 possibly the best candidate for storing and transporting H 2 . The conversion of NH 3 to energy has received very little attention, however. As part of this project we demonstrated the first example of a well-defined complex capable of driving electrocatalytic ammonia oxidation to N 2 , protons and electrons. We further thoroughly investigated the mechanistic underpinnings of the electrocatalytic reactions. We have also developed new chemistry to synthesize transition metal complexes aimed at increasing the efficiency and activity of electrocatalysts for the conversion of NH 3 to H 2 and N 2 at ambient temperatures.