First-principles study of oxygen evolution reaction on CeNi-doping Co3O4(110)

Abstract

Electrocatalytic water splitting driven by renewable electricity has become one of the most prospective and effective ways to solve energy issues. However, the practical process was limited by the development of electrocatalysts with high activity and low cost. In the search for new electrocatalysts, the researchers pay attention to the typical Co₃O₄ materials in oxygen evolution reaction (OER), due to its great electrocatalytic performance. In this work, using first-principles calculations, we studied the OER performance by adjusting the proportion and position of Ni (1∼8) and by fixing the Ce position on CeNi-Co₃O₄ (CeNiCo). It was found that the case of only one Ni doping (Ni^aCo^aCe) had the lower overpotential (0.22 V) with Co as active site and appropriate Ce-Ni distance than that of pure Co₃O₄ (0.36 V). Then, electron localization function showed that a degree of covalency Ce-O^Ni-Co (Ni in sublayer) in the case of Ni^aCo^aCe was higher than that of Co-O-Co in pure Co₃O_4. Furthermore, analyzing the density of states in different doping cases could understand the origin of distinct OER activity. Additionally, the results of formation energy and dissolution energy indicate that CeNiCo exhibits good stability when Ni is at a suitable position and in an appropriate proportion. Finally, ab initio molecular dynamics simulations (AIMD) also indicated that Ni^aCo^aCe had better thermodynamic stability. It was anticipated that our work will provide further insights into the effects of different doping number and positions on catalyst performance, and help guide the design and synthesis of more efficient OER catalysts in the future