(685c) Exploration of Novel Catalysts for Ammonia Synthesis: Creating a More Efficient Pathway

The utilization of fossil fuels and non-environmentally friendly industrial processes have created an environmental crisis. Thus, some research should be directed towards alternative, and more sustainable, energy carriers. Hydrogen has been a suggestion for a replacement fuel source¹, due to the lack of CO₂ released when reacted, however, hydrogen must be stored under high pressure to use as an energy dense fuel source. Ammonia is a possible option, due to the milder storage conditions required, the ubiquity of usable nitrogen, and the higher energy density compared to liquid-hydrogen². However, to make this alternative source viable, advancements in synthesis must be undertaken. The current pathway is derived from the Haber-Bosch process, which accounts for approximately 1.8% of all energy consumption in the world³. Current methods utilize reaction temperatures close to 450°C and pressures near 200bar. One pathway currently being explored is to reduce process severity, whilst also maintaining or improving the reaction rate of the process.

Our research focuses on utilizing novel ruthenium-based catalysts operating at lower temperatures and pressures using parallel and single reactors. Here, we have explored a range of metal-oxide supports, such as MgO, Pr₂O₃, and CeO₂; and promoters, including Yttrium, Potassium, Cesium, Tin, Scandium, and Hafnium that improve the efficiency and stability of the catalyst. Further, we attempted to minimize the ruthenium weight-loading on our catalysts to create more viable options for potential scale-up opportunities. These advancements could create a potential means to reducing carbon-emissions via greener fuel sources and reductions in energy usage during synthesis.

¹Department of Energy. DOE/EE-2128. Hydrogen Program Plan. November 2020. hydrogen.energy.gov/pdfs/hydrogen-program-plan-2020.pdf (Accessed 10 April 2022).

²Lan R and Tao S (2014) Ammonia as a suitable fuel for fuel cells. Front. Energy Res. 2:35.
doi: 10.3389/fenrg.2014.00035

³The Royal Society. Ammonia: zero-carbon fertiliser, fuel and energy store. February 2020. royalsociety.org/-/media/policy/projects/green-ammonia/green-ammonia-policy-briefing.pdf (Accessed 10 April 2022).