Study of oxygen evolution reaction on amorphous Au13@Ni120P50 nanocluster

Abstract

The pursuit of catalysts to promote effective water oxidization to produce oxygen has become a research subject of high priority for water splitting. Here, first-principles calculations are employed to study the water-splitting oxygen evolution reaction (OER) on ∼1.5 nm diameter Au₁₃@Ni₁₂₀P₅₀ core–shell nanoclusters. Water splitting to produce oxygen proceeds in four intermediate reaction steps (OH*, O*, OOH* and O₂). Adsorption configurations and adsorption energies for the species involved in OER on both Au₁₃@Ni₁₂₀P₅₀ cluster and Ni₁₂P₅(001) supported by Au are presented. In addition, thermodynamic free energy diagrams and kinetic potential energy changes are systematically discussed. We show that the third intermediate reaction (O* reacting with H₂O to produce OOH*) of the four elementary steps is the reaction-determining step, which accords with previous results. Also, the catalytic performance of OER for Au₁₃@Ni₁₂₀P₅₀ is better than that for Ni₁₂P₅(001) supported by Au in terms of reactive overpotential (0.74 vs. 1.58 V) and kinetic energy barrier (2.18 vs. 3.17 eV). The optimal kinetic pathway for OER is further explored carefully for the Au₁₃@Ni₁₂₀P₅₀ cluster. The low thermodynamic overpotential and kinetic energy barrier make Au₁₃@Ni₁₂₀P₅₀ promising for industrial applications as a good OER electrocatalyst candidate.