Highly effective Ru-based Heusler alloy catalysts for N2 activation: A theoretical study

In the present study, we investigate the catalytic ability of Heusler alloys towards N2 decomposition which is the main obstacle to nitrogen reduction reaction (NRR). First-principles methods were used to calculate the adsorption energies and dissociation barriers of nitrogen molecules on the (1 1 0) and (0 0 1) surfaces of Ru-based Heusler alloys (Ru2YZ, Y = Sc, Ti, V, Fe; Z = Sn, Ga, Ge, As, P). The electron-rich Ru atoms on the Ru-based Heusler alloy surfaces can significantly improve the adsorption activity and reduce the decomposed energy barrier of N2 molecules. A linear relationship between charges of all components, d-band-center, and N2 adsorption energy is predicted to reveal the factors that affect adsorption. The (0 0 1) surfaces of Ru2ScZ and Ru2TiZ are highly effective for N2 activation with lower N2 energy barriers around 0.4 eV. The unique catalytic performance of Ru-based Heusler alloys can be attributed to the synergistic role of the electronic effect and geometric effect of the active sites on the ordered alloy surfaces. Our theoretical results provide a strategy for the rational design of high-performance NRR electrocatalysts.