Interplay of H₂, water vapor and oxygenat the surface of SnO₂ based gas sensors - An operando investigation utilizing deuterated gases

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• 作者：Katharina Grossmann ; ^{Katharina.grossmann@ipc.uni-tuebingen.de}  ; [Author Vitae] ; Roman G. Pavelko¹  ; [Author Vitae] ; Nicolae Barsan  ; [Author Vitae] ; Udo Weimar  ; [Author Vitae]
• 关键词：DRIFTS ; Hydrogen sensing ; Tin dioxide sensor ; Isotopic exchange ; Surface reactions on tin dioxide
• 刊名：Sensors and Actuators B ; Chemical
• 出版年：2012
• 期刊代码：161_09254005
• 类别：et
• 出版时间：20 May, 2012
• 卷：166-167
• 期：Complete
• 页码：787-793
• 文件大小：864 K

摘要

The surface reactivity toward hydrogen and water vapor of three different (in grain size and amount of OH groups on the surface, different synthesis route) undoped tin dioxide materials (SnO₂ Ac, SnO₂Cl, SnO₂ Cl K) was investigated at 300 掳C by applying simultaneous resistance measurements and DRIFTS (diffuse reflectance infrared spectroscopy). The changes of the surface species, i.e. OH groups, were examined due to exposure to hydrogen H₂/deuterium D₂, watervapor H₂O/deuterated water vaporD₂O and carbon monoxide CO. A possibility to minimize IR related disturbing phenomena in the absorbance spectra is the use of deuterated gases (D₂, D₂O): everything which deals with OH groups/water related species is shifted in the IR spectrum. We were able to show that the reaction with those reducing gases can be traced back to the reaction with adsorbed oxygen. There was no evidence for a direct reaction of the test gas with OH groups or in case of H₂, a direct reaction with (lattice) oxygen to hydroxyl groups.