Quantification of Urea in Electrocatalytic Systems

Electrochemical urea synthesis (EUS) from CO 2 and nitrates has recently emerged as a more sustainable alternative to nitrogen fertilizers derived from fossil fuels. Indeed, using captured CO 2 and nitrates from wastewater can offer environmental benefits compared to conventional methods. On the road to EUS technology development, its accurate and reliable quantification is an undeniable cornerstone. As this field is still in its infancy, with very low product concentration and numerous side‐products, EUS product quantification is challenging, with reported false positives and negatives. Despite the consensus that at least two methods ought to be used, the selection of the most suitable methods and quantification protocols is an open topic in the scientific community. This work presents a comparative study of the most common methods, highlighting their advantages, limitations, and recent developments, aiming to provide valuable insights to guide the advancement of this emerging field and facilitate the upscaling of sustainable fertilizer production.