The effectiveness of the addition of diethylene glycol (DEG) to the impregnating solution in synthesizing highly dispersed Co-based catalysts supported on stabilized alumina (Al₂O₃^(s)) is investigated. Both the properties and catalytic performance in the Fischer-Tropsch synthesis (FTS) of the material obtained using DEG (CoDEG/Al₂O₃^(s)) are compared with those of a catalyst with the same formulation but prepared without the addition of DEG in the impregnating solution (Co/Al₂O₃^(s)). When using Co-nitrate as Co-precursor, the addition of DEG leads to a very fast and exothermic decomposition of Co-nitrate into Co oxides during the calcination step. This prevents the agglomeration of Co₃O₄ particles, thus generating highly dispersed Co₃O₄ crystallites on the support. In line with the decrease of the Co₃O₄ crystallites size, the CoDEG/Al₂O₃^(s) catalyst is more difficult to reduce than the Co/Al₂O₃^(s) catalyst. As a result, the metallic surface of the two catalysts is very similar. Nonetheless, when tested in the FTS, the CoDEG/Al₂O₃^(s) catalyst shows CO conversion higher than the Co/Al₂O₃^(s) sample. This is attributed to the high intrinsic activity (i.e. high Turnover Frequency, TOF) of the small Co⁰ crystallites of the CoDEG/Al₂O₃^(s) catalyst. We explain this result assuming that the combustion phenomenon occurring during the fast calcination induced by the presence of DEG may generate structural defects on the catalyst surface that are beneficial for the FTS. Notably, the product distribution of CoDEG/Al₂O₃^(s) catalyst is only slightly affected.

研究了在浸渍溶液中添加二甘醇（DEG）在合成负载在稳定化氧化铝（Al ₂ O ₃ ^（s））上的高分散Co基催化剂方面的有效性。将使用DEG（CoDEG / Al ₂ O ₃ ^（s））获得的材料的费-托合成（FTS）的性能和催化性能与相同配方但未添加DEG制备的催化剂进行比较在浸渍溶液中（Co / Al ₂ O ₃ ^（s））。当使用硝酸钴作为共母体时，在煅烧步骤中添加DEG会导致硝酸钴非常快速且放热地分解为钴氧化物。这防止了Co ₃ O ₄颗粒的团聚，从而在载体上产生了高度分散的Co ₃ O ₄晶体。随着Co ₃ O ₄晶粒尺寸的减小，CoDEG / Al ₂ O ₃ ^（s）催化剂比Co / Al ₂ O ₃ ^（s）催化剂更难还原。结果，两种催化剂的金属表面非常相似。但是，在FTS中进行测试时，CoDEG / Al₂ O ₃ ^（s）催化剂显示的CO转化率高于Co / Al ₂ O ₃ ^（s）样品。这归因于CoDEG / Al ₂ O ₃ ^（s）催化剂的小Co ⁰微晶的高固有活性（即高周转频率，TOF）。我们假设在DEG的存在引起的快速煅烧过程中发生的燃烧现象可能会在催化剂表面产生有利于FTS的结构缺陷的情况下解释这一结果。值得注意的是，CoDEG / Al ₂ O ₃ ^（s）催化剂的产物分布仅受到很小的影响。