Computational Design of Ni₆@Pt₁M₃₁ Clusters for Multifunctional Electrocatalysts

High-efficiency and low-cost multifunctional electrocatalysts for hydrogen evolution reaction (HERs), oxygen evolution reaction (OERs) and oxygen reduction reaction (ORRs) are important for the practical applications of regenerative fuel cells. The activity trends of core-shell Ni₆@M₃₂ and Ni₆@Pt1M31 (M = Pt, Pd, Cu, Ag, Au) were investigated using the density functional theory (DFT). Rate constant calculations indicated that Ni₆@Pt₁Ag₃₁ was an efficient HER catalyst. The Volmer-Tafel process was the kinetically favorable reaction pathway for Ni₆@Pt₁M₃₁. The Volmer-Heyrovsky reaction mechanism was preferred for Ni₆@M₃₂. The Pt active site reduced the energy barrier and changed the reaction mechanism. The ORR and OER overpotentials of Ni₆@Pt₁Ag₃₁ were calculated to be 0.12 and 0.33 V, indicating that Ni₆@Pt₁Ag₃₁ could be a promising multifunctional electrocatalyst. Ni₆@Pt₁M₃₁ core-shell clusters present abundant active sites with a moderate adsorption strength for *H, *O, *OH and *OOH. The present study shows that embedding a single Pt atom onto a Ni@M core-shell cluster is a rational strategy for designing an effective multifunctional electrocatalyst.