Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6642662 | Fuel | 2013 | 8 Pages |
Abstract
Cu/CeO2 (cop) was prepared by a coprecipitation method using NH3·H2O as a precipitant (in order to avoid the residues of alkali metals), followed by a boiling process to eliminate NH3 and decompose [Cu(NH3)4]2+ complex. Because the Cu particles in Cu/CeO2 (cop) were much smaller than those in Cu/CeO2 (imp) (prepared by an impregnation method), Cu/CeO2 (cop) showed a higher activity than that over Cu/CeO2 (imp) for the synthesis of mixed alcohols. Moreover, Cu/CeO2 (cop) showed a higher CO conversion than that over the industrial catalyst Cu/ZnO due to the reducibility of CeO2-based compounds. Although either Cu/ZnO or Cu/CeO2 (cop) produced methanol as a dominant product, the STY of higher alcohols (C2+OH) formed over Cu/CeO2 (cop) was much larger than that over Cu/ZnO because CeO2-based compounds could catalyze the synthesis of isobutane from syngas (isosynthesis). When Cs was introduced into the Cu/CeO2 (cop) catalyst, the mass ratio of C2+OH to MeOH in the products greatly increased from 0.13 to 0.71 but the CO conversion decreased slightly. Both the CO conversion and the selectivity for higher alcohols over CsCu/CeO2 (cop) were higher than those over CsCu/ZnO. By introducing Ni (an F-T element) into CsCu/CeO2 (cop), the CO conversion increased from 22.2% to 37.6% and the mass ratio of C2+OH to MeOH in the products increased from 0.71 to 0.85. Therefore, CsNiCu/CeO2 (cop) is an excellent catalyst for the synthesis of mixed alcohols. A slow deactivation was observed over CsNiCu/CeO2 (cop) in the reaction at 573 K for 18 h. The deactivated catalyst could be regenerated by calcination in air at 723 K and followed by reduction in H2 at 573 K.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Yanyong Liu, Kazuhisa Murata, Megumu Inaba, Isao Takahara, Kiyomi Okabe,