Platinum dissolution and restructuring due to surface oxidation are primary degradation mechanisms that limit the lifetime of platinum-based electrocatalysts for electrochemical energy conversion. Here, we have studied well-defined Pt(100) and Pt(111) electrode surfaces by in situ high-energy surface X-ray diffraction, online inductively coupled plasma mass spectrometry and density functional theory calculations to elucidate the atomic-scale mechanisms of these processes. The locations of the extracted platinum atoms after Pt(100) oxidation reveal distinct differences from the Pt(111) case, which explains the different surface stability. The evolution of a specific oxide stripe structure on Pt(100) produces unstable surface atoms that are prone to dissolution and restructuring, leading to one order of magnitude higher dissolution rates.

由于表面氧化而导致的铂溶解和重组是主要的降解机理，这些机理限制了用于电化学能量转换的铂基电催化剂的寿命。在这里，我们通过原位高能表面X射线衍射，在线感应耦合等离子体质谱和密度泛函理论计算研究了定义明确的Pt（100）和Pt（111）电极表面，以阐明原子级机理。这些过程。Pt（100）氧化后提取的铂原子的位置与Pt（111）情况显示出明显的差异，这说明了不同的表面稳定性。Pt（100）上特定氧化物条纹结构的演化产生不稳定的表面原子，这些原子易于溶解和重组，从而导致更高的溶解速率一个数量级。