Mark SymesABDULHAI HANI AHMED FAQEEH2022-06-062020-11-082022-06-0683592https://drepo.sdl.edu.sa/handle/20.500.14154/67638Ammonia is a chemical product in high demand worldwide, mainly produced by the Haber-Bosch process; however, this process has high energy consumption and generates enormous CO2 emissions. Hence, replacing this process with the electrochemical nitrogen reduction, which requires only electrons, atmospheric N2, and H+ produced from electrolytic water splitting, is attractive since the electrosynthesis of NH3 is a sustainable alternative to the Haber-Bosch process with zero carbon footprint. However, the nitrogen reduction process currently generates negligible amounts of NH3 compared to the Haber-Bosch process due to the sluggish kinetics of the nitrogen reduction reaction and the competing hydrogen evolution reaction (HER); consequently, developing highly stable electrocatalysts with high selectivity towards the nitrogen reduction reaction is required. Herein, the thermodynamics and electrocatalytic pathways of the nitrogen reduction reaction and the electrocatalytic activity criteria are illustrated. Moreover, several studies published in 2020 about precious and non-precious transition metal-based electrocatalysts divided into two subcategories (single-atom and nanocomposite electrocatalysts) are analysed and criticised by evaluating the electrocatalysts’ performance. The evaluation is based on analysing and criticising the procedures and protocols followed in conducting nitrogen reduction tests and investigating the stability of the electrocatalysts, the purity of the N2 sources, and verifying that NH3 is genuinely produced by the nitrogen reduction process. In other words, the evaluation ensures that the faraday efficiency and NH3 yield are achieved solely by the nitrogen reduction processes with different electrocatalysts.40enThesis