Possibilities to modify active centres on gas sensitive materials

Physicochemical properties and especially a kind of catalyst active centres play an important role in heterogeneous catalysis. Catalytic properties of metal oxides are not only widely used in typical chemical catalysis. Also chemical gas sensors widely use their catalytic properties. In these devices, materials are an active catalytic layer. Different catalytic reactions take place on the surface of these layers depending on the content of the surrounding atmosphere. The quality or physicochemical properties depend on their basic parameters like stability of gas sensitive material, its specific surface, porosity and kind or power of active centres that participate in chemical reactions. The paper presents research results in spectroscopy in infrared IR of gas sensitive materials based on SnO₂. These materials include different admixtures that modify their sensory properties. IR research studies have shown that modifying admixtures cause a distinct change in quality of active centres and their power.