First-Principles Study on the Electrocatalytic Oxygen Evolution Reaction on the (110) Surfaces of Layered Double Hydroxides

The electrochemical oxygen evolution reaction (OER) is a half-reaction of electrolytic water splitting for hydrogen production, which could provide a clean, efficient, and green strategy to construct a sustainable and renewable energy network. However, the OER is a four-electron oxidative reaction, which is a bottleneck of the water-splitting reaction with slow kinetics and a higher overpotential. In this paper, we investigated the performance of the OER of a series of layered double hydroxides (M32+N3+-LDHs, M2+ = Co2+, Ni2+, Zn2+, Mg2+, Ca2+, and N3+ = Co3+, Fe3+, Cr3+, Mn3+, Al3+) using the density functional theory (DFT) method, explored the mechanisms of OERs at three active sites (*M–M3N-LDH, *N–M3N-LDH, and *M(M)–M3N-LDH) on the (110) surfaces of LDHs, and constructed the volcano plot relationship between LDHs' OER catalytic activities and corresponding ΔG*O–ΔG*OH (ΔG*O: the adsorption free energies of *O intermediates, ΔG*OH: the adsorption free energies of *OH intermediates). The catalyst has a better catalytic activity when the adsorption of *O on the surfaces of LDHs is moderate. The calculated results show that Co3Fe-LDH(110) with the *Co–Co3Fe-LDH(110) site, Ni3Fe-LDH(110) with the *Fe–Ni3Fe-LDH(110) site, and Ni3Mn-LDH(110) with *Mn–Ni3Mn-LDH(110) and *Ni(Ni)–Ni3Mn-LDH(110) sites own potential excellent OER electrocatalytic activities. In addition, the effects of the band gaps and d-band centers on the OER catalytic performance of LDHs were discussed, showing that the decrease of the band gaps of LDHs could promote electron transport and could enhance their catalytic activity. For LDH catalytic systems containing 3d electrons, the d-band center is strongly related to the adsorption of *O on surfaces. Thus, the catalytic activities on the (110) surfaces of these LDH systems have a volcano diagram relationship with the d-band centers. This work could provide a theoretical basis for screening the optimal two-dimensional LDH catalysts for the OER.