炭化过程对铁基费托合成催化剂强度和结构的影响

摘要

以模型费托合成Fe基催化剂为研究对象,在纯CO气氛中对催化剂进行不同时间的预处理,采用多种手段对预处理后催化剂的物理化学性质和抗磨损能力进行了表征.结果表明,在预处理初期,随着预处理时间的延长,催化剂的炭化程度显著提高,伴随着催化剂比表面积的降低和颗粒粒径的减小,而催化剂的抗磨损能力逐渐提高.当预处理时间超过72 h后,继续延长预处理时间,催化剂的炭化程度不再增加,而积炭程度逐渐增加,伴随着催化剂比表面积和颗粒粒径的增加,催化剂的质量也同时增加,并导致催化剂的抗磨损能力逐渐降低.%In order to gain an insight into the relationship between pretreatment condition and catalyst attrition resistance,an iron-based model catalyst for Fisher-Tropsch synthesis was carburized at 300 ℃ for different times and extensively characterized by multiple techniques;the effect of carburization and carbon deposition on the catalyst attrition resistance was then investigated.The results indicated that at the initial stage of pretreatment,the carbide content increases with the increase of carburization time,whereas the BET surface area and particle size are decreased,leading to an increase in the catalyst attrition resistance.With further increasing the carburization time above 72 h,the carbide content keeps almost constant,whereas the carbon deposition content,particle size and catalyst weight are increased,accompanying with a decrease in the attrition resistance.