High-rate production of syngas with tunable H₂/CO and coke-free operation is achieved in a solid-oxide electrolysis cell (SOEC). Prior to operation, controlled pre-reduction of La_0.7Sr_0.3Fe_0.9Ni_0.1O_3-δ(LSFNi) cathode is used to trigger the in-situ exsolution of Ni-Fe alloy nanoparticles with an average size of ~45 nm uniformly distributed and socketed on LSFNi backbone, enabling efficient co-electrolysis of H₂O and CO₂ to H₂ and CO. At 1.5 V, the current density reaches ~1.0 A cm⁻² at 750 °C and ~2.4 A cm ⁻² at 850 °C with near 100% Faradaic Efficiency. We demonstrate the feasibility of tuning the output H₂/CO ratio by nearly two orders of magnitude (from ~0.1 to ~7) by manipulating H₂O/CO₂ ratio of feed gas, operating temperature, and current density. Stable operation for >100 h is obtained without evidence of carbon deposition, although high current density operation leads to observable deterioration of anode/electrolyte interface due to the rapid oxygen evolution.

在固态氧化物电解槽（SOEC）中，具有可调节的H ₂ / CO和无焦运行，可实现高产率的合成气生产。在操作之前，使用La _0.7 Sr _0.3 Fe _0.9 Ni _0.1 O3 _-δ（LSFNi）阴极的受控预还原来触发原位析出平均尺寸约为45 nm的Ni-Fe合金纳米粒子并插在LSFNi主链上，从而实现H ₂ O和CO ₂高效共电解为H ₂和CO。在1.5 V时，电流密度在750°C和〜2.4 A cm ^-2时达到〜1.0 A cm ^-2在850°C时具有接近100％的法拉第效率。我们证明了通过控制原料气的H ₂ O / CO ₂比，工作温度和电流密度，将输出H ₂ / CO比调节近两个数量级（从〜0.1到〜7）是可行的。尽管电流密度高，由于氧气的快速释放会导致阳极/电解质界面的可观察到的劣化，但仍可获得100小时以上的稳定运行而没有碳沉积的迹象。