Reconstructed fluorine doped perovskites for electrocatalytic urea production through reaction pathways with CO2 and nitrate ions

Abstract

Electrochemical urea synthesis is under developing as a cutting-edge technology poised to meet substantial demand in an energy-efficient and highly promising way. However, challenges, such as low faraday efficiency and yield rate, have promoted extensive research and experimentation to overcome these obstacles. This research investigated electrocatalytic urea synthesis using fluorine-doped strontium ferrite as an endurable structure, demonstrating superior performance in urea formation when fluorine doping regulated A-site vacancy for the structural reconstruction of catalytic surface in a CO2 environment. The reconstructed fluorine-doped strontium ferrite catalyst achieved a high Faraday efficiency of 35.77 % and an impressive production rate of 2087 mg g−1 h−1 in an H-cell, with stability over 15 cycles. In-situ Raman spectroscopy successfully identified intermediates, and DFT calculations showed that the reconstruction of catalytic surface facilitates urea synthesis by providing more favorable electronic structure due to the lower d-band center of Fe for both C-N coupling and CO2 reduction. This insight confirmed that a small amount of dopant can maintain catalyst performance through its post-reconstruction and contribute significantly to the development of durable electrocatalyst materials.