为研究黏结剂二氧化硅的导入条件对沉淀铁基费托合成催化剂的结构及性能的影响，通过调变黏结剂的导入温度、陈化时间、pH值制备了不同的催化剂样品。利用低温N2物理吸附、XRD、磨损测试、H₂-TPR等手段对样品进行表征，并在固定床反应器上进行费托合成反应评价，考察了黏结剂导入的工艺参数对催化剂的织构特性、晶相结构、抗磨损强度和费托合成反应性能的影响。XRD结果表明，不同的催化剂样品均呈水合氧化铁的晶相结构，不同的黏结剂导入的工艺参数对催化剂的物相结构并无影响。低温N₂物理吸附结果表明，提高黏结剂导入温度、延长黏结剂导入后的陈化时间、降低黏结剂导入时的pH值使催化剂的孔体积略微增大，而对比表面积几乎没有影响。磨损测试结果表明，当黏结剂导入温度升高、导入后的陈化时间延长时，催化剂的磨损指数先下降后升高，表明这两个参数存在最佳范围。从长周期费托合成反应评价结果上看，在55 ℃下导入黏结剂制备的催化剂失活速率最低、选择性最佳。结合磨损测试结果，55 ℃左右应为导入黏接剂的最佳温度。当陈化时间延长至210 min时，催化剂的CO转化活性降低，稳定性变差。随黏结剂导入pH值的降低，催化剂的抗磨损强度明显提高。结合H₂-TPR表征结果，降低黏结剂导入的pH值使铁-硅之间的相互作用增强是催化剂强度提高的主要原因。

In order to investigate the effect of binder addition parameter on the structure and performance of iron based Fischer Tropsch synthesis catalysts,a series of Fe Cu K SiO₂ catalysts were prepared by varying the parameters including temperature,pH value and aging time during binder precursor addition.The effect of binder addition parameters on both physical chemical properties and FT synthesis performance of those catalysts were investigated using low temperature N₂ physical adsorption,XRD,Air jet cup attrition test,H₂ TPR and activity test on fixed bed reactor.The XRD results indicate that all of the samples exhibit same bulk structure of ferrihydrite,while the different binder addition parameters have no effect on the crystalline structure of those catalysts.Based on the N₂ physical adsorption results,the pore volume of the catalysts becomes larger in narrow range as the result of increasing temperature,aging time and decreasing pH value of binder induction procedure.The attrition index decreases first and then increases as the temperature and aging time of binder induction increase,indicating that there are optimized conditions for these two parameters to improve the overall catalyst’s attrition performance.As the result of activity tests,the sample binder induced under 55 ℃ exhibits the lowest deactivation rate as well as the best selectivity.The CO conversion of the catalyst decreases when the aging time of binder induction is prolonged until 210 min.Attrition index of the catalyst decreases obviously when the binder is induced under lower pH value.The results of H2 TPR indicate that the increased Fe O Si SMSI should be responsible for the increased attrition properties of the catalysts.

1 试验部分

   1.1 试剂

   1.2 催化剂的制备

   1.3 催化剂的表征

   1.4 催化剂的评价

   1.5 产物分析

2 结果与讨论

   2.1 黏结剂的导入工艺参数对催化剂结构的影响

   2.2 黏结剂的导入工艺参数对催化剂性能的影响

3 结论