Electrochemical reduction of NOx

Publication: ResearchPh.D. thesis – Annual report year: 2012

Standard

Electrochemical reduction of NOx. / Traulsen, Marie Lund; Kammer Hansen, Kent (Supervisor).

Department of Energy Conversion and Storage, Technical University of Denmark, 2012. 225 p.

Publication: ResearchPh.D. thesis – Annual report year: 2012

Harvard

Traulsen, ML & Kammer Hansen, K 2012, Electrochemical reduction of NOx. Ph.D. thesis, Department of Energy Conversion and Storage, Technical University of Denmark.

APA

Traulsen, M. L., & Kammer Hansen, K. (2012). Electrochemical reduction of NOx. Department of Energy Conversion and Storage, Technical University of Denmark.

CBE

Traulsen ML, Kammer Hansen K 2012. Electrochemical reduction of NOx. Department of Energy Conversion and Storage, Technical University of Denmark. 225 p.

MLA

Traulsen, Marie Lund and Kent Kammer Hansen Electrochemical reduction of NOx Department of Energy Conversion and Storage, Technical University of Denmark. 2012.

Vancouver

Traulsen ML, Kammer Hansen K. Electrochemical reduction of NOx. Department of Energy Conversion and Storage, Technical University of Denmark, 2012. 225 p.

Author

Traulsen, Marie Lund; Kammer Hansen, Kent (Supervisor) / Electrochemical reduction of NOx.

Department of Energy Conversion and Storage, Technical University of Denmark, 2012. 225 p.

Publication: ResearchPh.D. thesis – Annual report year: 2012

Bibtex

@phdthesis{a26865f4a97d4a08a1a9fe2085841c47,
title = "Electrochemical reduction of NOx",
publisher = "Department of Energy Conversion and Storage, Technical University of Denmark",
author = "Traulsen, {Marie Lund} and {Kammer Hansen}, Kent",
year = "2012",

}

RIS

TY - BOOK

T1 - Electrochemical reduction of NO<sub>x</sub>

A1 - Traulsen,Marie Lund

AU - Traulsen,Marie Lund

A2 - Kammer Hansen,Kent

ED - Kammer Hansen,Kent

PB - Department of Energy Conversion and Storage, Technical University of Denmark

PY - 2012

Y1 - 2012

N2 - NO and NO2 (collectively referred to as NOx) are air pollutants, and the largest single contributor to NOx pollution is automotive exhaust. This study investigates electrochemical deNOx, a technology<br/>which aims to remove NOx from automotive diesel exhaust by electrochemical reduction of NOx to N2 and O2. The focus in this study is on improving the activity and selectivity of solid oxide electrodes for electrochemical deNOx by addition of NOx storage compounds to the electrodes. Two different composite electrodes, La0.85Sr0.15MnO3-δ-Ce0.9Gd0.1O1.95 (LSM15-CGO10) and<br/>La0.85Sr0.15FeO3-δ-Ce0.9Gd0.1O1.95 (LSF15-CGO10), have been investigated in combination with three different NOx storage compounds: BaO, K2O and MnOx. The main focus in the investigation has been on conversion measurements and electrochemical characterization, the latter by means of electrochemical impedance spectroscopy and cyclic voltammetry. In addition, infrared spectroscopy has been performed to study how NOx adsorption on the electrodes is affected by the presence of the aforementioned NOx storage compounds. Furthermore, non-tested and tested electrode microstructures have been thoroughly evaluated by scanning electron microscopy.<br/>The studies reveal addition of MnOx or K2O to the electrodes cause severe degradation problems, and addition of these compounds is thus unsuitable for electrode improvement. In contrast, addition of BaO to LSM15-CGO10 electrodes is shown to have a very positive impact on the NOx conversion. The increased NOx conversion, following the BaO addition, is attributed to a combination of 1) a decreased electrode polarisation resistance and 2) an altered NOx adsorption. The NOx conversion is observed to increase strongly with polarisation, and during 9 V polarisation of an 11-layer porous cell stack, 60% NOx conversion in a mixture of 1000 ppm NO and 10% O2 is achieved at 400 °C on entirely ceramic electrodes.<br/>This project thus demonstrates electrochemical deNOx is possible without the presence of noble metals at realistic operating conditions. However, several questions remain, among these how the BaO interacts with the solid oxide electrodes and how the electrochemical cell is optimally operated during electrochemical deNOx.

AB - NO and NO2 (collectively referred to as NOx) are air pollutants, and the largest single contributor to NOx pollution is automotive exhaust. This study investigates electrochemical deNOx, a technology<br/>which aims to remove NOx from automotive diesel exhaust by electrochemical reduction of NOx to N2 and O2. The focus in this study is on improving the activity and selectivity of solid oxide electrodes for electrochemical deNOx by addition of NOx storage compounds to the electrodes. Two different composite electrodes, La0.85Sr0.15MnO3-δ-Ce0.9Gd0.1O1.95 (LSM15-CGO10) and<br/>La0.85Sr0.15FeO3-δ-Ce0.9Gd0.1O1.95 (LSF15-CGO10), have been investigated in combination with three different NOx storage compounds: BaO, K2O and MnOx. The main focus in the investigation has been on conversion measurements and electrochemical characterization, the latter by means of electrochemical impedance spectroscopy and cyclic voltammetry. In addition, infrared spectroscopy has been performed to study how NOx adsorption on the electrodes is affected by the presence of the aforementioned NOx storage compounds. Furthermore, non-tested and tested electrode microstructures have been thoroughly evaluated by scanning electron microscopy.<br/>The studies reveal addition of MnOx or K2O to the electrodes cause severe degradation problems, and addition of these compounds is thus unsuitable for electrode improvement. In contrast, addition of BaO to LSM15-CGO10 electrodes is shown to have a very positive impact on the NOx conversion. The increased NOx conversion, following the BaO addition, is attributed to a combination of 1) a decreased electrode polarisation resistance and 2) an altered NOx adsorption. The NOx conversion is observed to increase strongly with polarisation, and during 9 V polarisation of an 11-layer porous cell stack, 60% NOx conversion in a mixture of 1000 ppm NO and 10% O2 is achieved at 400 °C on entirely ceramic electrodes.<br/>This project thus demonstrates electrochemical deNOx is possible without the presence of noble metals at realistic operating conditions. However, several questions remain, among these how the BaO interacts with the solid oxide electrodes and how the electrochemical cell is optimally operated during electrochemical deNOx.

BT - Electrochemical reduction of NO<sub>x</sub>

ER -