Investigation of an Impedimetric LaSrMnO3-Au/Y2O3-ZrO2-Al2O3 Composite NOx Sensor

Abstract

Composite NOx sensors were fabricated by combining partially and fully stabilized yttria-doped zirconia with alumina forming a composite electrolyte, Y2O3-ZrO2-Al2O3, and strontium-doped lanthanum manganese oxide mixed with gold to form the composite sensing electrode, La0.8 Sr0.2MnO3-Au. A surface chemistry analysis of the composite sensor was conducted to interpret defects and the structural phases present at the Y2O3-ZrO2-Al2O3 electrolyte, as well as the charge conduction mechanism at the LaSrMnO3-Au electrode surface. Based on the surface chemistry analysis, ionic and electronic transport properties, and microstructural features of sensor components, the working principle was described for NOx sensing at the composite sensor. The role of the composite materials on the NOx sensing response, cross-sensitivity to O2, H2O, CO, CO2, and CH4, and the response/recovery rates relative to sensor accuracy were characterized by operating the composite NOx sensors via the impedimetric method. The composite sensors were operated at temperatures ranging from 575 to 675 °C in dry and humidified gas environments with NO and NO2 concentrations varying from 0 to 100 ppm, where the balance gas was N2. It was found that the microstructure of the composite NOx sensor electrolyte and sensing electrode had a significant effect on interfacial reactions at the triple phase boundary, as well as the density of active sites for oxygen reactions. Overall, the composite NOx sensor microstructure enabled a high NOx sensing response, along with low cross-sensitivity to O2, CO, CO2, and CH4, and promoted NO detection down to 2 ppm.

Quantum mechanical analysis of yttrium-stabilized zirconia and alumina: implications for mechanical performance of esthetic crowns

“…In terms of esthetics, YSZ can be matched in color to more natural teeth, and additional translucency adds to the more natural appearance of restorations. It is suitable for both anterior and posterior teeth [ 20 ].…”

Adsorption Behavior of NO and NO2 on Two-Dimensional As, Sb, and Bi Materials: First-Principles Insights

“…Consequently, there is a growing need for nitrogen oxide gas detectors characterized by high sensitivity, selectivity and stability. Various methods of NO X detection have been published, including electrochemical gas sensors [ 11 , 12 , 13 ], optical gas sensors [ 14 ], and semiconductor gas sensors [ 15 , 16 , 17 ]. Compared with alternative gas sensors, semiconductor gas detectors display heightened sensitivity and affordability.…”

The explanation of electrical properties changes under NH3 and H2 containing atmospheres in risen temperatures of ceria- and zirconia-based solid electrolytes by means of electrochemical impedance spectroscopy

“…Its mechanical and chemical properties make it valuable as a prosthetic material for medicine or constructive material for industry. Moreover, high ionic electrical conductivity and temperature shock tolerance of the stabilised ZrO 2 make it suitable for application in oxygen sensors [26][27][28][29][30], solid oxide fuel cells [31][32][33][34], ceramic components and as catalyst or catalysts promoters in the synthesis of alcohols by hydrogenation of CO [35][36][37][38].…”