Advances and challenges with SOEC high temperature co-electrolysis of CO2/H2O: Materials development and technological design

Higher electrolysis efficiency than that achieved with conventional electrolysis and integrated fuel production would help to reduce dependence on bio-energy further. In this regard, solid oxide electrolyzer (SOEC) technology is of particular interest because of its unrivaled conversion efficiency, due to the favorable thermodynamics and kinetics at higher operating temperatures. In particular, SOEC high-temperature co-electrolysis (HTCE) of CO₂/H₂O can convert CO₂ into valuable chemicals and fuels, which will help to reduce reliance on fossil fuels and mitigate greenhouse gas emissions. In this report, we present a comprehensive overview of recent research progress made with SOEC HTCE of CO₂/H₂O. The main focus areas are the development history, the basic principle and the reaction mechanism of HTCE of CO₂/H₂O using SOEC. The fuel electrode and oxygen electrode materials for SOEC HTCE of CO₂/H₂O are classified and introduced. The factors that affect the co-electrolysis reaction process are also described in detail, and the optimization strategy of the process conditions is explained to provide a better understanding of the SOEC HTCE process. The challenges and possible future development directions are also suggested, as guidance for future research.