期刊
JOURNAL OF CATALYSIS
卷 382, 期 -, 页码 57-68出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcat.2019.12.007
关键词
Cobalt ferrite; Selective oxidation; Surface spectroscopy; 2-Propanol; Deactivation
资金
- Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within the collaborative research centre/transregio TRR 247 Heterogeneous Oxidation Catalysis in the Liquid Phase [388390466, 405034883]
- European Research Council under grant ERC-OPERANDOCAT [ERC-725915]
CoFe2O4 nanoparticles (NPs) were synthesized by using a colloidal one-pot synthesis method based on the decomposition of metal acetylacetonates in the presence of oleyl amine. The characterization by X-ray diffraction, transmission electron microscopy and N-2 physisorption revealed non-porous spinel phase CoFe2O4 NPs with an average particle size of 4 nm. The unsupported metal oxide NPs were applied in the selective oxidation of 2-propanol in a continuously operated fixed-bed reactor under quasi steady-state conditions using a heating rate of 0.5 k min(-1). 2-Propanol was found to be oxidatively dehydrogenated over CoFe2O4 yielding acetone and H2O with high selectivity. Only to a minor extent dehydration to propene and total oxidation to CO2 was observed at higher temperatures. The detected low-temperature reaction pathway with maxima at 430 and 510 K was inhibited after the initial 2-propanol oxidation up to 573 K, but an oxidative treatment in O-2 or N2O atmosphere led to full regeneration. No correlation between the desorbing amount or the surface oxygen species investigated by O-2 temperature programmed desorption experiments and the low-temperature activity was observed. The amounts of evolving CO2 during the TPO experiments indicate deactivation due to formation of carbonaceous species. Inhibition experiments with pre-adsorbed reaction intermediates and infrared spectroscopy identified acetate species as reversible poison, whereas carbonates are rather spectators. In addition, carbon deposition was detected by X-ray photoelectron spectroscopy, which also revealed a minor influence of cobalt reduction during the deactivation process as confirmed by X-ray absorption spectroscopy studies. (C) 2019 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据