Semester

Spring

Date of Graduation

2012

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Nianqiang Wu.

Abstract

Carbon monoxide (CO) is one of the major air pollutants which are emitted due to the incomplete combustion of hydrocarbon fuels. It is a colorless, odorless and tasteless gas that is highly toxic to humans and animals. Hence, a CO sensor not only serves as an alarm system for threat of CO, but also be used for monitoring the combustion process to improve the combustion efficiency. The currently existing technologies to detect CO such as gas chromatography and optical absorption spectrometry are cumbersome, costly, and lack the capability of on-line monitoring. Thus there is a critical need for developing CO sensors that can give accurate and fast response to change in the concentrations of CO as low as 20 ppm at high temperature (> 500 °C).;In the present work, La0.8Sr0.2MnO3 (LSM) nanofibers were prepared by electrospinning method and utilized as a mixed potential sensor electrode for sensing CO at high temperature. The nanofibers show good thermal stability even after heat treatment at 1050 °C. This nano-fibrous structure possesses several advantages such as high porosity, high surface to volume ratio and high activity towards CO electrochemical oxidation. The nanofibers bring improved sensitivity and lower the limit of detection as compared with bulk LSM powders. Electrochemical impedance (EIS) analysis indicated that the nano-fibrous electrode shows better charge transfer capability, leading to improved catalytic activity for CO oxidation and sensor performance. The developed sensor can be used for monitoring emissions from coal-fired power plants and vehicle exhausts.

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