Dataset of "Structural Development on Ru and RuO2 Electrodes during Oxygen Evolution – an operando soft X-ray Absorption Spectroscopy Approach"

Time resolved in-situ X-ray absorption spectroscopy (XAS) in soft X-ray region was used to characterize polarized interphase on Ru and Ru oxide based electrodes under oxygen evolution reaction (OER) conditions. XAS spectra were used to align the type and population of oxygen-containing species formed at electrodes at anodic potentials with local electronic structure of the OER catalyst. The operando soft XAS data do not identify a single rate limiting process at potentials negative to 1.4 V vs Ag/AgCl. Individual intermediates of the oxygen evolution process coexist at the surface at potentials preceding the actual OER onset. The OER is accompanied with redistribution of the electron density resulting for a start of the catalytic cycle reflecting increased population of oxygen vacancies at the surface. The observed spectral behavior indicates a confinement of the OER to the coordination unsaturated sites (cus) at the surface.本研究采用软X射线能区的时间分辨原位X射线吸收光谱（XAS），对析氧反应（OER）工况下钌（Ru）及氧化钌基电极表面的极化界面开展表征。借助XAS光谱，将阳极电位下电极表面生成的含氧物种的种类与丰度，与OER催化剂的局域电子结构进行关联匹配。相较于Ag/AgCl参比电极，在电位低于1.4 V的区间内，该工况原位软XAS数据未观测到单一限速步骤。在实际OER起始电位之前的电位区间内，析氧过程的各反应中间体共存于电极表面。析氧反应伴随电子密度重分布，进而启动催化循环，该过程体现为电极表面氧空位丰度的提升。观测到的光谱行为表明，析氧反应局限于电极表面的配位不饱和位点（cus）。