Combined XRD and XANES studies of a Re-promoted Co/γ-Al2O3 catalyst at Fischer-Tropsch synthesis conditions
Combined XRD and XANES studies of a Re-promoted Co/γ-Al2O3 catalyst at Fischer-Tropsch synthesis conditions
复制标题
DOI：
10.1016/j.cattod.2009.10.010
复制
发表时间：
2010-10-15
期刊：
影响因子：
5.3
通讯作者：
Holmen, Anders
中科院分区：
文献类型：
--
作者：
Ronning, Magnus;Tsakoumis, Nikolaos E.;Holmen, Anders
在工业条件下，对反应初期的钴基Fischer-Tropsch催化剂进行了研究。催化剂由20wt%的钴担载在γ-Al_2O_3上，1wt%的Re助剂组成。用X射线衍射仪(XRD)和X射线吸收近边结构(XANES)相结合的方法，揭示了活性组份的氧化状态和颗粒大小的信息。比较了对轻烃具有高选择性的条件(甲烷化、673K、10bar和高GHSV)与较高选择性的条件(483K、18bar和低GHSV的FT合成)。数据分析表明，在费托合成的最初几个小时内，钴的微晶没有明显的变化。在更高的温度和主要是甲烷化的条件下进行反应会导致钴颗粒的显著烧结，并可以观察到部分还原的催化剂进一步还原。(C)2009爱思唯尔B.V.保留所有权利。
A cobalt based Fischer-Tropsch catalyst was studied during the initial stages of the reaction at industrially relevant conditions. The catalyst consists of 20 wt% cobalt supported on gamma-Al2O3 and promoted by 1 wt% of rhenium. X-ray diffraction (XRD) in combination with X-ray absorption near edge structure (XANES) were used to reveal information on the particle and crystallite size and the oxidation states of the active component. Conditions giving high selectivity towards light hydrocarbons (methanation, 673 K, 10 bar and high GHSV) were compared to conditions were higher hydrocarbons are the main products (FT synthesis at 483 K, 18 bar and low GHSV). The data analysis shows no significant changes in the cobalt crystallites during the first hours of Fischer-Tropsch synthesis. Running the reaction at higher temperatures and predominantly methanation conditions led to significant sintering of the cobalt particles and a further reduction of a partially reduced catalyst could be observed. (C) 2009 Elsevier B.V. All rights reserved.