Fischer-Tropsch Synthesis: Assessment of the Ripening of Cobalt Clusters and Mixing between Co and Ru Promoter via Oxidation-Reduction-Cycles over Lower Co-Loaded Ru-Co/Al2O3 Cat

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• 作者：Gary Jacobs ; Amitava Sarkar ; Yaying Ji ; Mingsheng Luo ; Alan Dozier ; Burtron H. Davis
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2008
• 出版时间：February 6, 2008
• 年：2008
• 卷：47
• 期：3
• 页码：672 - 680
• 全文大小：719K
• 年卷期：v.47,no.3(February 6, 2008)
• ISSN：1520-5045

文摘

A 2% Ru-promoted 15% Co/Al₂O₃ catalyst was tested after reduction and after being subjected to oxidation-reduction cycles. The catalysts were characterized over four oxidation-reduction cycles by XANES/EXAFS,TPR, HRTEM, and EDS elemental mapping. The oxidation-reduction treatments were found to assist insintering the metallic clusters to a larger size, and to promote mixing on at least the order of the nanoscale.The larger crystallites in closer proximity to the Ru promoter led to a more facile reduction of the cobaltcrystallites. In addition, a catalyst exposed to two oxidation-reduction cycles resulted in slightly higherconversion, higher -value product, slightly lower methane selectivity, and greater stability over a reducedfreshly calcined catalyst.