Designing V Single Atom Embedded Carbon Moiety for the Electrocatalytic Nitrogen Reduction Reaction by First Principles Study

Development of an efficient electrocatalyst for the nitrogen reduction reaction (NRR) to serve as a sustainable alternative to the Haber-Bosch process has proven highly challenging. Single atom catalysts (SACs), which have the maximum atom utilization efficiency, are among the most promising candidates. Single atoms can be incorporated to a catalytic system by doping or substitution or by attaching a molecular coordination complex to a substrate and the different insertion modes allow the chemical environment to be varied. We have used DFT to investigate vanadium SACS for NRR activity with a focus on varying the coordination environment of the V atom. Phthalocyanine, porphyrin and graphene like coordination environments with varying N-coordination have been studied. Vanadium phthalocyanine (V_phN₄) is the most promising of the investigated systems. It features high selectivity relative the HER reaction and relatively strong binding of N₂ relatively H, which prevents poisoning of the surface by hydrogen. V_phN₄ also has the lowest overpotential among the studied systems. The electrocatalytic properties of V_phN₄ deposited as a monolayer on the Ag (111) surface have been investigated. This system, which already has been prepared, shows promising properties for use as a catalytic electrode for the NRR reaction.