In operando, ambient-pressure x-ray photoelectron spectroscopy (AP-XPS) has been used to evaluate surface states of gadolinia-doped ceria (GDC) thin-film electrodes during H₂ oxidation and H₂O electrolysis, on yttria-stabilized zirconia (YSZ)-supported solid oxide electrochemical cells (SOCs). Porous nickel (Ni) and gold (Au) overlayers deposited on separate GDC thin films served as current collectors and potential electrocatalysts to facilitate heterogeneous chemistry for H₂ oxidation or H₂O electrolysis. Electrochemical characterization of the GDC thin-film electrodes complemented in operando XPS measurements of the O 1s spectra to correlate electrochemical overpotentials with surface chemistry near the Ni/GDC and Au/GDC interfaces. Shifts in O 1s binding energies across the metal/GDC/YSZ interfaces signified changes of local surface potential and provided a means of estimating kinetic parameters associated with charge transfer reactions. Effective oxygen partial pressure and surface potential impacted oxide vacancy and ceria polaron concentrations in the GDC, resulting in different reactivities of the GDC under the tested conditions. Both the Ni/GDC and Au/GDC demonstrated much higher currents for H₂O electrolysis vs. H₂ oxidation for comparable metal/GDC overpotentials due to increased electronic conductivity of the GDC under positive potentials and associated spreading of the electrochemically active region away from the triple-phase boundary. Higher electrochemical activity of the Ni/GDC electrode is attributed to the increased H₂ activation on Ni in promoting charge transfer reactions (particularly for H₂ oxidation). These results provide a basis for developing more informed reaction mechanisms for both H₂ oxidation and H₂O electrolysis of GDC-based composite electrodes in SOCs.

在操作中，常压X射线光电子能谱（AP-XPS）已用于评估氧化钇稳定的氧化锆上H ₂氧化和H ₂ O电解过程中掺g的二氧化铈（GDC）薄膜电极的表面状态。（YSZ）支持的固体氧化物电化学电池（SOC）。沉积在单独的GDC薄膜上的多孔镍（Ni）和金（Au）覆盖层用作集电器和潜在的电催化剂，以促进H ₂氧化或H _2的多相化学反应O电解。GDC薄膜电极的电化学特性在Oss光谱的操作XPS测量中得到补充，以使电化学超电势与Ni / GDC和Au / GDC界面附近的表面化学物质相关联。O 1s结合能在金属/ GDC / YSZ界面上的移动表示局部表面电势的变化，并提供了一种估算与电荷转移反应相关的动力学参数的方法。有效的氧分压和表面电势会影响GDC中的氧化物空位和二氧化铈极化子浓度，导致在测试条件下GDC的反应性不同。与H ₂相比，Ni / GDC和Au / GDC的H ₂ O电解电流都高得多由于在正电势下GDC的电子电导率增加以及电化学活性区域远离三相边界的扩散，导致可比较的金属/ GDC超电势发生氧化。Ni / GDC电极的较高电化学活性归因于Ni在促进电荷转移反应（特别是对于H ₂氧化）中对H _2的活化增加。这些结果为开发SOC中基于GDC的复合电极的H ₂氧化和H ₂ O电解的更灵敏的反应机理提供了基础。