Measurement of Pt electrode surface area of automotive ZrO2 oxygen sensors
| Autor: | R.K. Usmen, Mordecai Shelef, E. M. Logothetis |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Metals and Alloys
Analytical chemistry chemistry.chemical_element engineering.material Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Adsorption chemistry Methanation law Electrode Materials Chemistry engineering Flame ionization detector Noble metal Electrical and Electronic Engineering Platinum Dispersion (chemistry) Instrumentation Oxygen sensor |
| Zdroj: | Sensors and Actuators B: Chemical. 28:139-142 |
| ISSN: | 0925-4005 |
| DOI: | 10.1016/0925-4005(95)80039-5 |
| Popis: | Platinum loading and metal dispersion have been measured in the outer, sensing electrodes of four commercial heated exhaust-gas oxygen (HEGO) sensors which have previously been thoroughly characterized. The Pt dispersion is determined by methanation of adsorbed CO with H2 with the quantification of the CH4 formed in the process by a flame ionization detector. The outer electrodes differ by a factor of four in Pt loading. The lowest loading is noted on the sensor that is inert in the oxidation of small saturated hydrocarbon molecules under the evaluation conditions of the previous characterization. In all sensors the dispersion of the Pt is very low, with only 1–3 atoms in 103 directly accessible to the gas phase. This technique is applicable to other gas sensors that similarly contain noble metal additives with a very low surface area. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect