Details

Autor(en) / Beteiligte

• Zhang, Xiaoyu
• Wang, Hui
• Jiang, Xiao
• Sun, Hongchun
• Qu, Zhenping

Titel

Study of synergistic effect between CuO and CeO 2 over CuO@CeO 2 core–shell nanocomposites for NH 3 -SCO

Ist Teil von

• Catalysis science & technology, 2019-06, Vol.9 (11), p.2968-2981

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Cerium oxides were orientally introduced into copper oxide phases to improve the catalytic performance of the CuO catalyst for the selective catalytic oxidation of ammonia (NH 3 -SCO). A series of CuO@CeO 2 - X ( X = 2, 4, 8, and 16) core–shell nanocomposites was fabricated from Cu 2 O cubic particles via the template-assisted method involving the liquid (Ce( iv ))–solid (Cu 2 O) interfacial reaction and tested as catalysts. Their compositions, structures, catalytic activities and reaction route were studied in detail through HRTEM, XRD, XPS and Raman spectroscopy. The results demonstrated that the synergism between CuO and CeO 2 at their interface is enhanced gradually with the formation of the core–shell structure, which facilitates the formation of the Cu–O–Ce structure (solid solution). The CuO@CeO 2 -8 catalyst with a complete core–shell structure showed the highest catalytic activity, especially at a low temperature (7.0 × 10 −2 μmol g −1 s −1 at 180 °C), and the lowest reaction activation energy ( E a = 29.1 J mol −1 ) among the samples. In addition it was found that the synergistic effect between CuO and CeO 2 effectively improves the adsorption and activation of ammonia species from NH 3 -TPD and NH 3 + O 2 experiments. Also, more NO intermediate species form on the Cu–O–Ce structure than N 2 O intermediates, which is conductive to achieve high N 2 selectivity following the iSCR route.