Are transition metal phthalocyanines active for urea synthesis electrocatalytic coupling of CO and N?

Electrocatalytic coupling of CO and N to synthesize urea presents a promising approach to address global energy and environmental challenges. Despite the potential, developing an efficient catalyst capable of activating both CO and N while suppressing side reactions remains a significant challenge. Recent studies have indicated that CuPc and CoPc exhibit notable activity in this process. Herein, we report a theoretical analysis of the catalytic performance of 3d-5d transition metal phthalocyanines (MPcs) in the electrocatalytic urea synthesis reaction. Our findings reveal that MPcs generally exhibit limited activity due to the poor competitiveness of N for adsorption sites and the high energy barrier associated with CO-N coupling, which hinders their ability to compete with CO reduction and/or N reduction pathways. Furthermore, the coupling between CO and NH* is either insufficient for N reduction or is outcompeted by ammonia formation. We propose that enhancing N adsorption could facilitate C-N coupling, offering a potential strategy for the design of single-atom catalysts aimed at improving urea synthesis efficiency.