Catalytic conversion of syngas to olefins over Mn-Fe catalysts

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• 作者：Saleh A. Al-Sayari
• 关键词：Conversion ; Syngas ; Olefins ; Mn&ndash ; Fe catalysts
• 刊名：Ceramics International
• 出版年：January, 2014
• 年：2014
• 卷：40
• 期：1_part_PA
• 页码：723-728
• 全文大小：1409 K

文摘

A series of MnO₂-Fe₂O₃ with various contents of Mn (0-40% atomic ratio) was synthesized by the co-precipitation method. XRD patterns indicate that the sharp and intense peaks are related to the excellent crystal quality of 伪-Fe₂O₃ nanostructures. HR-TEM images showed that 伪-Fe₂O₃ and MnO₂, were partly in close contact and the lattice fringes exhibit the typical distances, i.e., 伪-Fe₂O₃ (104) (2.7 脜) and MnO₂ (310) (3.1 脜). X-ray photoelectron spectroscopy (XPS) results of the Fe 2p core-level binding energy spectrum of the 伪-Fe₂O₃ and Mn 2p, indicated the presence of Fe³⁺ and Mn⁴⁺. The direct synthesis of olefins from syngas was carried out over the MnO₂-Fe₂O₃ catalysts under pressurized fixed-bed continuous flow conditions. The results showed that Mn-Fe catalyst had high catalytic activity and high olefins selectivity without the addition of any promoters at low pressure. It was found that the catalyst containing 20 at% Mn-Fe was an optimal catalyst for the conversion of synthesis gas to hydrocarbons especially light olefins. The maximum CO conversion rate was 15%, and the yield of olefins (totally about 23.77%) with a predominance of CH₄ (12.24%), and C₂H₆ (2.80%) components. Mn-Fe catalyst can be regarded as a potential candidate for catalytic conversion of biomass-derived syngas to olefins.