Recent innovations in urea synthesis via electrochemical C-N coupling reaction: insights and perspectives
摘要
Among nitrogen-based fertilizers, urea is the most important and dominant candidate, with an approximate share of 50% in the agriculture market, utilizing about 2% of the worldwide energy for its industrial-scale production. In turn, the process accounts for about 3% of the carbon dioxide (CO2) emissions globally, which subsequently contributes to the energy crisis, greenhouse gas emissions, and global warming. These carbon emission figures imply a strict and urgent need for the development of alternative, sustainable, and efficient methodologies for environmentally friendly urea production. The electrochemical C-N coupling approach for urea synthesis is a sustainable alternative approach being explored to slowly replace the existing energy-consuming industrial urea production process. The electrochemical urea synthesis is currently in its nascent stage, and at present this technology is far from industrial-scale application, and hence, herein we present this review, which highlights the mechanism for urea synthesis, recent breakthroughs and developments, while highlighting the challenges associated with electrochemical urea synthesis. In order to further enhance reaction efficiency and selectivity, electrocatalysts play a vital part in the electrochemical urea production pathways; however, a number of constraints, such as the need for superior catalyst performance, understanding of complicated chemical pathways, and process scalability for industrial use still need to be conquered. This review highlights research on the recent developments in electrochemical urea synthesis and sheds light on the requirements for a feasible process to give guidance and directions for future research work.