A thermodynamic and kinetic study of the catalytic performance of Fe, Mo, Rh and Ru for the electrochemical nitrogen reduction reaction

Abstract

The electrochemical reduction of N2 is a promising candidate to ammonia synthesis process. Density functional theory simulations are carried out to study the reaction thermodynamics and kinetics for better understanding...

Theoretical Insights on Au‐based Bimetallic Alloy Electrocatalysts for Nitrogen Reduction Reaction with High Selectivity and Activity

“…As can be seen from Table S3c, the adsorption sites and adsorption configurations of N 2 and N 2 H on Mo 3 Au(111) have not changed. Therefore, comparing with the previous calculation results of Mo(110) surface, the product reorganization energies on Mo 3 Au(111) are significantly reduced [40] …”

“…Based on Marcus charge transfer theory, the activation energy is calculated by reorganization energy and Gibbs free‐energy change as Equation (3). Under the equilibrium potential (the Gibbs free‐energy change equals 0), the activation energy is only determined by the reorganization energy of the reactants ( λ R ) and the reorganization energy of the products ( λ P ) [40,45–47] . We draw the contour map of activation barrier as a function of λ R and λ P at equilibrium potential.…”

“…It was found that Mo, Fe, Rh, and Ru are the most active surfaces, but the competing HER is quite serious [7] . In addition, our previous work has further verified that the electrocatalytic NRR activity of pure metals is Fe>Mo>Ru>Rh [40] . We have selected the three most active metals (Fe, Mo, Ru) to form alloy with Au.…”

“…A large number of investigations have proved that Mo plays a significant role in N 2 activation in different types of NRR catalysts [9,36–39] . On the other hand, much work has been accomplished by researchers to study the activity of the pure metals in NRR including our previous work [7,23,40] . Yang and co‐workers proposed (110)‐oriented Mo nanofilm could achieve a rate of NH 3 formation of 3.09×10 −11 mol s −1 cm −2 under an applied potential of −0.49 V (vs. RHE) [41] …”

“…Unlike the CI‐NEB method, a kinetic model based on the Marcus charge transfer theory was successfully used to calculate the potential‐dependent reaction barrier of concerted proton‐electron transfer (CPET) steps in the electrochemical NRR and CO 2 RR process. In this approach, the proton derives from electrolyte solution, and the electron comes from the electrode [40] . The reaction barriers were composed of reaction free‐energy change and reorganization energy.…”