Max-Planck-Institut für Kohlenforschung, Department of Heterogeneous Catalysis, 45470 Mülheim an der Ruhr, Germany.
Molecules. 2019 Sep 3;24(17):3199. doi: 10.3390/molecules24173199.
We report a varying temperature infrared spectroscopic (VTIR) study with partial deuterium isotopic exchange as a method for characterizing proton mobility in acidic materials. This VTIR technique permits the estimation of activation energies for proton diffusion. Different acidic materials comprising classical proton-conducting materials, such as transition metal phosphates and sulfonated solids, as well as different zeolites, are tested with this new method. The applicability of the method is thus extended to a vast library of materials. Its underlying principles and assumptions are clearly presented herein. Depending on the temperature ranges, different activation energies for proton transfer are observed irrespective of the different materials. In addition to the well-studied transition metal phosphates, Si-rich zeolites appear to be promising proton-transfer materials (with E < 40 kJ mol) for application in high-temperature (>150 °C) PEM fuel cells. They significantly outperform Nafion and sulfonated silica, which exhibit higher activation energies with E ~ 50 and 120 kJ mol, respectively.
我们报告了一种变温红外光谱（VTIR）研究，其中部分氘同位素交换作为一种表征酸性材料中质子迁移率的方法。这种 VTIR 技术可以估计质子扩散的活化能。不同的酸性材料包括经典的质子导体材料，如过渡金属磷酸盐和磺化固体，以及不同的沸石，都用这种新方法进行了测试。因此，该方法的适用性扩展到了大量的材料库。本文清楚地介绍了其基本原理和假设。根据温度范围的不同，无论材料不同，都观察到不同的质子转移活化能。除了研究充分的过渡金属磷酸盐外，富硅沸石似乎是有前途的质子转移材料（E < 40 kJ mol），可用于高温（>150°C）质子交换膜燃料电池。它们的性能明显优于 Nafion 和磺化硅，后者的活化能分别为 E ~ 50 和 120 kJ mol。
