Oxygen Evolution Reaction over the Au/YSZ Interface at High Temperature.

The oxygen evolution reaction (OER) is a sluggish electrocatalytic reaction in solid oxide electrolysis cells (SOECs) at high temperatures (600-850 °C). Perovskite oxide has been widely investigated for catalyzing the OER; however, the formation of cation-enriched secondary phases at the oxide/oxide interface blocks the active sites and decreases OER performance. Herein, we show that the Au/yttria-stabilized zirconia (YSZ) interface possesses much higher OER activity than the lanthanum strontium manganite/YSZ anode. Electrochemical characterization and density functional theory calculations suggest that the Au/YSZ interface provides a favorable path for OER by triggering interfacial oxygen spillover from the YSZ to the Au surface. In situ X-ray photoelectron spectroscopy results confirm the existence of spillover oxygen on the Au surface. This study demonstrates that the Au/YSZ interface possesses excellent catalytic activity for OER at high temperatures in SOECs.