Electrocatalytic process for ammonia electrolysis: a remediation technique with hydrogen co-generation

Abstract

Alkaline ammonia electrocatalysis offers a favorable technique for hydrogen generation and simultaneous conservation of environmental sustainability. In this work, the electrooxidation of ammonia on platinum-Iridium (Pt-Ir) electrocatalyst was studied in 5 M potassium hydroxide (KOH) solution. The effects of operating conditions such as, temperature and ammonia (NH3) concentration were investigated. Ammonia electrooxidation current density increased at elevated temperature and ammonia concentration. The maximum ammonia conversion was 78 % for 2300 ppm ammonia. Furthermore, the maximum hydrogen flow rate obtained was 25 L/ h and the corresponding energy consumption is 1.6 W h/ L-H2. The hydrogen purity obtained from the gas chromatography was 86 %. Ammonia is poisonous to the proton exchange membrane (PEM), hence ammonia ion selective electrode was used to determine the amount of ammonia present in H2 gas stream produced and was found to be < 0.1ppm