Wrinkle structure control of carbon nitride catalyst for electrocatalytic nitrogen reduction reaction

Abstract

Ammonia is a necessary substance for the production of chemical fertilizers and is produced through nitrogen reduction reaction. Catalysts suitable for ammonia synthesis using electrocatalysis are being studied to reduce greenhouse gas emissions from the existing Haber-Bosch process and to carry out the reaction with low energy at room temperature and pressure. In order to increase the low faradaic efficiency of the electrochemical catalyst and the amount of ammonia production, it is necessary to reduce the hydrogen evolution reaction while using a material advantageous for nitrogen activation. In this study, the efficiency of the electrochemical nitrogen reduction reaction was improved by using a carbon nitride polymer catalyst having a wrinkle structure. The wrinkle structure inhibits the hydrogen evolution reaction by accumulating hydroxide ions in the wrinkle, raising the local pH. The wrinkle structure catalyst was manufactured by sequentially stacking carbon nanotubes and carbon nitride polymer on a polystyrene film using vacuum filtration, and then using a simple wrinkle manufacturing process at high temperature. The wrinkled carbon nitride polymer catalyst showed 1.58 times and 1.63 times higher faradaic efficiency and ammonia yield than the flat film-structured carbon nitride polymer catalyst at room temperature and atmospheric pressure.