Charge transfer dynamics in RuO₂/perovskite nanohybrid for enhanced electrocatalysis in solid oxide electrolyzers

Coupled electrical, thermal catalysis of water or CO₂ splitting in solid oxide electrolysis cell (SOEC) offers an efficient route for energy storage. One of the key challenges to its industrialization is the lack of efficient electrocatalyst for oxygen evolution at the anode, especially when the operating temperature is pushed to its lower limit. Here we present advances to tackle this challenge by taking the advantages of the charge transfer dynamics in the junction RuO₂/perovskite, which enable the high SOEC performance at reduced temperatures. At 1.6 V and 600 °C, the modified SOEC delivers a current density of ~ 2.26 A cm^–2, and such high performance is maintained after 90 h. Most importantly, we substantially demonstrate the built-in charge transfer in the junction RuO₂/perovskite and disclose the electron donation from the Co-O bonding orbitals to the RuO₂ cluster. Overall, this work demonstrates a step change in the design of confined electrodes for reduced temperature SOEC, and it provides a general strategy for the functionalization of solid state material.