文献类型：期刊文献

英文题名：Influence of copper loading on the surface species and catalytic properties in the formation of oxygenated by-products during FTS over FeCuKLa/SiO 2 catalysts

作者：Mao, Wan-Yu[1]; Ma, Hong-Fang[1]; Zhang, Hai-Tao[1]; Sun, Qi-Wen[2]; Ying, Wei-Yong[1]; Fang, Ding-Ye[1]

机构：[1] State Key Laboratory of Chemical Engineering, Ministry of Education, East China University of Science and Technology, Shanghai 200237, China; [2] State Key Laboratory of Coal Liquefaction and Coal Chemical Technology, Shanghai 201203, China

年份：2012

卷号：142

期号：9

起止页码：1098

外文期刊名：Catalysis Letters

收录：EI(收录号：20123515375724)

语种：英文

外文关键词：Acetaldehyde - Silica - Copper - Copper compounds - Fourier transform infrared spectroscopy - Hydrogenation - Iron - Reflection - Catalysts - Adsorption - Molecules - Iron compounds - Lanthanum compounds

摘要：The influence of copper loading on the surface species and catalytic properties of Fe-Cu-K-La/SiO2 catalyst in the formation of oxygenated by-products during Fischer-Tropsch synthesis was investigated by temperature-programmed reduction (TPR), temperature-programmed desorption of CO and acetaldehyde (CO-, acetaldehyde-TPD), in situ diffuse reflectance FTIR and chemical trapping. The results showed that addition of copper improved the reducibility of catalysts, however, the adsorption features of catalysts changed significantly. Fe-Cu-K-La-SiO2 with a composition of 1:0.28:0.05:0.05:0.17 (molar ratio, relative to iron) had highest selectivity for hydrocarbons and lowest selectivity for C2+ oxygenates. Results of FTIR and chemical trapping indicated that extra copper would suppress CO adsorption as well as oxidation of adsorbed molecules. The stability of intermediates weakened simultaneously. Moreover, the quantitative estimates of the concentration of the surface species by acetaldehyde-TPD allowed the illustration of copper effect on the catalytic properties. Graphical Abstract: FTIR spectra of adsorbed species formed from CO + H2 interaction on Fe-K-La/SiO2 catalyst with different copper loadings: (a) 0.08; (b) 0.18; (c) 0.28; (d) 0.31; (e) 0.48: (A) 553 K, 3.5 MPa; (B) spectra after switching to pure H2. In-situ reaction was investigated which confirmed the results obtained in previous characterization including CO hydrogenation reaction, temperature-programmed desorption of adsorbed CO and acetaldehyde (CO-, acetaldehyde-TPD), in situ diffuse reflectance FTIR of methanol and acetaldehyde adsorption and chemical trapping. It could be seen that extra copper caused no apparent changes toward hydrogen which pointed to an unfavorable mobility of products formed on the catalytic surface and could be associated with the reduced reactivity of adsorbed molecules and weakened stability of intermediates with high copper loadings.[Figure not available: see fulltext.] ? 2012 Springer Science+Business Media, LLC.