Adsorption of Cun (n = 1‒4) clusters on CuAl2O4 spinel surface: A DFT study

•The adsorption energies for single Cu atom adsorbed on CuAl2O4 (100) and (110) surfaces are −4.46 and −3.27 eV, respectively.•The adsorption of single Cu atom on the oxygen-defective surface is weaker than on the perfect CuAl2O4 surface.•The adsorption of Cu on the spine surface is accompanied by charge transfer.•The interaction of Cu with CuAl2O4 surface is much stronger than with the γ-Al2O3(110) surface.