Solid Oxide Cells for Power‐to‐X: Advances, Challenges, and Pathways to Carbon‐Neutral Fuels and Chemicals

Solid oxide electrolysis cells (SOECs) represent a critical technology for integrating intermittent renewable electricity into the chemical and fuel production sectors, promising higher electrical efficiency than low‐temperature alternatives due to superior operating kinetics. While traditionally optimized for H ₂ generation, the actual value of high‐temperature co‐electrolysis lies in synthesizing complex, drop‐in fuels and industrial feedstocks—a domain known as Power‐to‐X (P2X). This review examines the paradigm shift from basic H ₂   production to integrated P2X pathways, highlighting recent advancements in materials that specifically enable multi‐electron transfer reactions. We detail the electrochemical routes for producing high‐value products such as syngas, synthetic methane, methanol, and ammonia, as well as emerging processes like direct CO ₂ conversion to hydrocarbons and high‐efficiency hydrocarbon upgrading. Crucially, we analyze the current state of electrochemical performance, stability challenges, and provide a techno‐economic perspective on the commercial readiness of SOEC stacks, positioning this technology as a foundational pillar for industrial decarbonization.