RuO₂ is commercially employed as an anode catalyst in the chlor-alkali process. It is also one of the most active electrocatalysts for the oxidation of water, relevant to electrochemical water splitting. However, the use of RuO₂ is limited by its low anodic stability under acidic conditions, especially at high overpotentials. In the present work, the electrochemical stability of model RuO₂(110)/Ru(0001) anodes was investigated in order to gain a deeper understanding of the relation between structure and performance in Cl₂ and O₂ evolution reactions (CER and OER, respectively). Online electrochemical mass spectrometry was used to determine the onset potential of CER and OER in HCl and H₂SO₄ electrolytes, respectively. The onset potential of OER was higher in HCl than in H₂SO₄ due to competition with the kinetically more favorable CER. A detailed stability evaluation revealed pitting corrosion of the electrode surface with exposure of Ru(0001) metal substrate concomitant with the formation of a hydrous RuO₂ in some areas regardless of the applied electrochemical treatment. However, despite local pitting, the RuO₂(110) layer preserves its thickness in most areas. Degradation of the electrode was found to be less severe in 0.5 M HCl due to a decrease in the faradaic efficiency of RuO₂ oxidation caused by competition with the kinetically more favorable CER.

RuO ₂在商业上用作氯碱工艺中的阳极催化剂。它也是水氧化最活跃的电催化剂之一，与电化学水分解有关。然而，RuO ₂的使用受到其在酸性条件下，特别是在高过电势下的低阳极稳定性的限制。在目前的工作中，研究了RuO ₂（110）/ Ru（0001）模型阳极的电化学稳定性，以便更深入地了解Cl ₂和O ₂析出反应中的结构与性能之间的关系（CER和OER，分别）。在线电化学质谱法用于确定CER和OER在HCl和H _2中的起始电位分别使用SO ₄电解质。由于与动力学上更有利的CER竞争，因此HCl中OER的起始电位高于H ₂ SO ₄。详细的稳定性评估表明，无论采用何种电化学处理方法，Ru（0001）金属基材的暴露都会伴随电极的水化RuO ₂的形成而暴露出电极表面的点蚀。然而，尽管有局部点蚀，RuO ₂（110）层仍可在大多数区域保持其厚度。发现电极的降解在0.5 M HCl中不太严重，这是由于与动力学上更有利的CER竞争引起的RuO ₂氧化法拉第效率的降低。