Title: Copper oxide shape effect in CeO₂/Cu₂O catalysts for PROX reaction

Authors: Jiyeon Kim; Hyunjoo Lee

Addresses: Department of Chemical and Biomolecular Engineering, Yonsei University, Sinchon-dong, Seodaemun-Gu, Seoul 120-749, South Korea ' Department of Chemical and Biomolecular Engineering, Yonsei University, Sinchon-dong, Seodaemun-Gu, Seoul 120-749, South Korea

Abstract: Cubic and octahedral Cu₂O nanocrystals were used as supports for ceria deposition. Ceria tended to deposit on the vertexes and edges of the nanocrystals more. Whisker type of ceria was deposited on Cu₂O surface. The prepared CeO₂/Cu₂O composite materials were tested as catalysts for preferential oxidation (PROX) reaction of CO in the presence of abundant H₂. As the amount of ceria became higher (e.g., 1 wt% vs. 10 wt%), CO conversion was higher. Cubic nanocrystals showed higher activity than octahedral nanocrystals, especially at lower temperature region. Also, the activity depended significantly on the oxidation state of copper oxide. When CeO₂/Cu₂O catalysts were oxidised first then used for PROX reaction, the activity was enhanced. Cu₂O turned into CuO with a slight shape change after oxidation at 400°C. The activity degraded at higher reaction temperature because the copper oxide was reduced to metallic copper.

Keywords: shape effect; copper oxide; ceria deposition; oxidation; nanocatalysts; PROX; nanotechnology; nanocrystals; composites.

DOI: 10.1504/IJNT.2013.054214

International Journal of Nanotechnology, 2013 Vol.10 No.8/9, pp.735 - 748

Published online: 01 Aug 2013 *

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