Enhanced electropromotion of methane combustion on palladium catalysts deposited on highly porous supports

Authors:  F. Matei, C. Jiménez-Borja, J. Canales-Vázquez, S. Brosda, F. Dorado, J.L. Valverde, D. Ciuparu

Abstract:
The aim of the present study was to explore the potential to electrochemically promote the methane oxidation reaction over palladium catalyst-electrodes deposited on a combination of porous-dense Y₂O₃- stabilized-ZrO₂ (YSZ), an oxygen ion conductor. We have prepared for the first time an electro-active palladium catalyst on a highly porous support, which was successfully used to enhance the catalytic activity by electrochemical promotion (NEMCA effect or EPOC). The wet impregnation technique has been used over highly porous YSZ disks to achieve very active catalyst-electrodes, with a metal catalyst dispersion of 27% (up to 4.5 times higher than that obtained for catalysts supported on dense YSZ), and susceptible to be electropromoted, despite its relatively high in-plane electrical resistance. The sample impregnated on porous YSZ turned to be much more active in methane combustion than the sample prepared by impregnation on dense YSZ, reaching, under similar working conditions, one order of magnitude higher CO₂ formation rates. The catalyst supported on porous YSZ was characterized by XRD, XPS, SEM and TEM techniques, while galvanostatic transients and electrochemical current–potential curves were recorded in order to assess the electropromotion of the catalytic reaction in a temperature range from 350 to 430 ◦C under reducing, stoichiometric and oxidizing conditions.

Keywords:
Methane oxidation
Electrochemical promotion
NEMCA
Pd catalyst-electrode
Porous YSZ

Published in: Applied Catalysis B: Environmental (Volumes 132–133, Pages 1-552, 27 March 2013)

Publisher: Elsevier  

ISSN Information: 0926-3373

Enhanced electropromotion of methane combustion on palladium catalysts deposited on highly porous supports

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