Catalyst Design of Delafossite Oxides for Water Electrolysis Anode Using Theoretical Calculations

Understanding the oxygen evolution reaction (OER) is crucial for improving the performance of water electrolysis. Delafossite oxides (ABO₂) were investigated for their potential as OER catalysts using density functional theory (DFT) calculations. The relationships between the calculated e_g or t_2g occupancy of the B site and the experimentally-determined OER activity were examined. Our examination suggests that t_2g electrons of the B site can be significant for the OER process. The calculated t_2g occupancy is approximately linearly related to OER activity. Thus, we propose that t_2g occupancy can be employed as a simple descriptor of the OER activity of delafossite oxide catalysts.