High-temperature CO₂ electrolysers offer exceptionally efficient storage of renewable electricity in the form of CO and other chemical fuels, but conventional electrodes catalyse destructive carbon deposition. Ceria catalysts are known carbon inhibitors for fuel cell (oxidation) reactions; however, for more severe electrolysis (reduction) conditions, catalyst design strategies remain unclear. Here we establish the inhibition mechanism on ceria and show selective CO₂ to CO conversion well beyond the thermodynamic carbon deposition threshold. Operando X-ray photoelectron spectroscopy during CO₂ electrolysis—using thin-film model electrodes consisting of samarium-doped ceria, nickel and/or yttria-stabilized zirconia—together with density functional theory modelling, reveal the crucial role of oxidized carbon intermediates in preventing carbon build-up. Using these insights, we demonstrate stable electrochemical CO₂ reduction with a scaled-up 16 cm² ceria-based solid-oxide cell under conditions that rapidly destroy a nickel-based cell, leading to substantially improved device lifetime.

高温CO ₂电解槽以CO和其他化学燃料的形式提供了可再生电力的高效存储，但是传统的电极催化了破坏性的碳沉积。二氧化铈催化剂是已知的用于燃料电池（氧化）反应的碳抑制剂。然而，对于更严格的电解（还原）条件，催化剂的设计策略仍然不清楚。在这里，我们建立了对二氧化铈的抑制机制，并显示出选择性CO ₂到CO的转化率远超过热力学碳沉积阈值。CO ₂期间的Operando X射线光电子能谱电解-使用由掺杂sa的二氧化铈，镍和/或氧化钇稳定的氧化锆组成的薄膜模型电极-结合密度泛函理论模型，揭示了氧化碳中间体在防止碳积聚中的关键作用。利用这些见解，我们证明了在迅速破坏镍基电池的条件下，采用放大的16 cm ²氧化铈基固体氧化物电池可以稳定地减少电化学CO _2的排放，从而显着提高了设备​​的使用寿命。