Many industrial chemical processes involve a high-energy demand (often still derived from fossil fuels). Urea is an important chemical for the agricultural industry, which accounts for 70% of the global nitrogen-containing fertilizer usage. Currently, urea is produced by the reaction of liquid NH3 and CO2[1] in a process known as the Haber-Meiser process. Despite its importance, this process suffers from high energy demand and CO2 emissions, mainly due to the NH3 synthesis step (Haber- Bosch process), which relies on fossil fuel resources. Making urea with electrochemical methods has recently gained interest from the scientific community as this approach provides a way to reduce the high CO2 emissions currently associated with urea production. Among the various nitrogen sources explored for urea electrosynthesis, nitrate (NO3-) is attractive because of its high solubility in water, low dissociation energy and potential to mitigate NO3− contaminations in water. Even though the mechanism of urea synthesis via CO2 and NO3- coupling is still controversial and not broadly studied, most reports implicate CO* and NH2* surface intermediates in urea synthesis.[2] Cu is an attractive electrocatalyst as it can reduce CO2 to CO and further products and it is also an active catalyst for the reduction of nitrate to ammonia Previous reports on Cu and Cu-based materials showed that urea can be obtained from NO2-.[3,4] Early research by Shibata et al. with various catalysts demonstrated that the highest faradaic efficiency towards urea from NO3- was achieved with a Zn catalyst.[5] In this presentation, I will show our latest results on the development of Cu bimetallic catalysts ( CuRh) for urea electrosysnthesis from CO2 and NO3-[6,7].

Refer to: https://iopscience.iop.org/article/10.1149/MA2024-01392331mtgabs