First-principles study of O2 adsorption and dissociation on the CuCr2O4 (100) surface

The adsorption and dissociation of molecular oxygen on spinel CuCr2O4 (100) surface were carried out by first-principles calculations based on density functional theory (DFT). The calculated results indicate that the Cr site is most favorable for atomic oxygen adsorption, with an adsorption energy of 402.8 kJ/mol. For molecular oxygen adsorption, there are three types of favorable interaction modes: O2 forms bonds with the Cu site or O2 binds to two Cr sites or O2 interacts with both Cu and Cr sites simultaneously. The lowest activation energy (Ea = 35.4 kJ/mol) was found through exploring possible reaction pathways for O2 dissociation. The relationship between Ea and reaction enthalpy (ΔH) for O2 dissociation adsorption reactions fits Brønsted-Evans-Polanyi (BEP) behavior.