(66a) Atomistic Deficiency of Lattice Oxygen for High Catalytic Activity in the Oxygen Evolution Reaction

Development of oxygen evolution reaction (OER) electrocatalysts with high current density, low overpotential and good stability is essential for many applications including hydrogen generation, CO₂ reduction, and Li-air batteries. However, OER performance is hindered by the sluggish reaction kinetics. Recently, it was reported that the introducing of oxygen deficiency to OER catalysts can enhance the reaction performance, resulting from the participation of the lattice oxygen-mediated mechanism instead of the conventional reaction mechanism. We previously developed Y₂Ru₂O₇ as a promising OER catalyst with one of highest performance in acidic media. In this work, we introduced and quantified the oxygen deficiency in Y₂Ru₂O₇ and studied its effect on OER performance. The obtained oxygen deficient Y₂Ru₂O_7-δ exhibited lowered overpotential and good stability in acidic electrolyte, demonstrating that oxygen deficiencies facilitate the OER reaction. The reaction mechanism for the elevated activity was further analyzed by density functional theory calculation. Other oxygen-deficient catalysts were also prepared and showed to exhibit enhanced OER performance. This work provides a new method of preparing and controlling oxygen-deficient OER catalysts with high performance and sheds light on the reaction mechanism related to lattice oxygen.