Sabatier principle based design of high performance FeCoNiMnMoP high entropy electrocatalysis for alkaline water splitting

FeCoNi-based high entropy intermetallic compounds are promising substitutes for noble metal catalysts for hydrogen evolution reaction (HER) and oxygen evolution (OER), while their activity is restricted by the synergistic effect between the elements. In this paper, the theoretical model of FeCoNiMnMoP bifunctional catalyst has been reasonably designed given the volcanic curve of M−H bond energy as a valuable guide for candidate metal elements. Theoretical calculations show that the synergistic effect between multiple sites not only accelerates the electron transfer but also reduces the rate-determining step (RDS) barrier. At the same time, the introduction of Mo also enhances the total density of states and reduces the d-band center, thus optimizing the adsorption and dissociation of intermediates. The experimental results confirm that the theoretical model has excellent catalytic performance. In the alkaline solution, FeCoNiMnMoP‖FeCoNiMnMoP requires only an ultra-low cell voltage of 1.49 V for overall water splitting when the current density is 10 mA cm −2 . In general, novel insights on the effects of intermetallic synergies on water decomposition are provided, which is helpful for the design of bifunctional catalysts based on volcanic diagrams.