Tuebingen University, Faculty of Science, Department of Chemistry, Institute of Physical and Theoretical Chemistry, Auf der Morgenstelle 15, 72076 Tübingen, Germany.
Phys Chem Chem Phys. 2013 Nov 28;15(44):19151-8. doi: 10.1039/c3cp52782d.
The impact of Pt doping on the surface reactions between tin dioxide, water vapour, CO and H2 was investigated by a combination of simultaneously performed operando DRIFT (Diffuse Reflectance Infrared Fourier Transform) spectroscopy, DC resistance measurements and analysis of the reaction products by using a MS (Mass Spectrometer). Both undoped and Pt doped tin dioxide sensors were exposed to different test gases in synthetic air or in N2 backgrounds. The approach made it possible to identify the differences between the two materials with respect to their surface chemistry and their impact on the gas sensing performance. The main finding is that the presence of Pt changes the reaction partners' nature for water vapour and H2 on the one hand, and CO on the other hand when the sensors are operated in air. In this way the cross interference effect of humidity, which is responsible for the loss of CO sensing performance for the sensors based on undoped SnO2, is reversed.
通过同时进行的原位漫反射红外傅里叶变换光谱（DRIFT）、直流电阻测量以及使用质谱仪（MS）分析反应产物的方法，研究了 Pt 掺杂对二氧化锡、水蒸气、CO 和 H2 之间表面反应的影响。将未掺杂和 Pt 掺杂的二氧化锡传感器暴露于合成空气中或 N2 背景下的不同测试气体中。这种方法使得能够确定两种材料在表面化学及其对气体传感性能的影响方面的差异。主要发现是，当传感器在空气中工作时，Pt 的存在一方面改变了水蒸气和 H2 的反应伙伴的性质，另一方面也改变了 CO 的反应伙伴的性质。这样，湿度的交叉干扰效应就被逆转了，这种效应是导致基于未掺杂 SnO2 的传感器失去 CO 传感性能的原因。
