Solar Urea: Towards a Sustainable Fertilizer Industry

Abstract

Abstract Urea, an agricultural fertilizer, nourishes humanity. The century‐old Bosch–Meiser process provides the world's urea. It is multi‐step, consumes enormous amounts of non‐renewable energy, and has a large CO 2 footprint. Thus, developing an eco‐friendly synthesis for urea is a priority. Herein we report a single‐step Pd/LTA‐3A catalyzed synthesis of urea from CO 2 and NH 3 under ambient conditions powered solely by solar energy. Pd nanoparticles serve the dual function of catalyzing the dissociation of NH 3 and providing the photothermal driving force for urea formation, while the absorption capacity of LTA‐3A removes by‐product H 2 O to shift the equilibrium towards urea production. The solar urea conversion rate from NH 3 and CO 2 is 87 μmol g −1 h −1 . This advance represents a first step towards the use of solar energy in urea production. It provides insights into green fertilizer production, and inspires the vision of sustainable, modular plants for distributed production of urea on farms.