Nicollet Clement, Meyssonnier Clement, Guillonneau Simon, Merieau Alexandre, Abdouli Insaf
Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, Nantes, F-44000, France.
Small Methods. 2024 Dec;8(12):e2400131. doi: 10.1002/smtd.202400131. Epub 2024 May 16.
Oxygen exchange reaction on mixed conducting oxide is a critical reaction for many applications, yet measuring its rate constant remains poorly reliable by standard techniques. Here, a new technique that adapts the conductivity relaxation measurements on porous ceramics is proposed. Using a simple image analysis tool, it is possible to accurately determine the grain size distribution of the porous oxide, which is used in a new relaxation model that integrates relaxation times over that distribution. With such a model, it is possible to fit relaxation transients with the oxygen exchange reaction rate constant k as the only fitting parameter. With such rigidity, the output values of k are not sensitive to the fitting procedure, which does not require optimization. The model is proven to be applicable to various mixed conducting oxides and to a wide range of microstructures, yielding a remarkably low residual for all the porous ceramics considered. The procedure uses porous ceramics, therefore the derived kinetics are representative of ceramics used in real applications such as fuel cells, sensors, or catalysis.
混合导电氧化物上的氧交换反应是许多应用中的关键反应，但通过标准技术测量其速率常数的可靠性仍然很差。在此，提出了一种适用于多孔陶瓷电导率弛豫测量的新技术。使用简单的图像分析工具，可以准确确定多孔氧化物的晶粒尺寸分布，该分布用于一个新的弛豫模型，该模型在该分布上对弛豫时间进行积分。有了这样一个模型，就可以用氧交换反应速率常数k作为唯一的拟合参数来拟合弛豫瞬变。由于具有这样的严格性，k的输出值对拟合过程不敏感，该过程不需要优化。该模型被证明适用于各种混合导电氧化物和广泛的微观结构，对于所有考虑的多孔陶瓷都产生了非常低的残差。该程序使用多孔陶瓷，因此推导得到的动力学代表了燃料电池、传感器或催化等实际应用中使用的陶瓷。
