硫代硫酸铵对CoMo和NiMoP催化剂的预硫化

Presulfidation of CoMo and NiMoP Catalysts by Ammonium Thiosulfate

采用硫代硫酸铵预硫化CoMo和NiMoP催化剂,考察了预硫化剂的负载量对催化剂加氢脱硫活性的影响.对于CoMo催化剂,预硫化剂含量适中,氢气活化后脱硫活性优于硫化氢硫化的对照催化剂.预硫化过程中产生的SO42–可修饰Al2O3载体,减弱了活性相与金属的相互作用,这可能是催化剂活性增加的原因.硫代硫酸铵含量过低,导致催化剂硫化不完全,脱硫活性下降,而硫化剂含量过高,使活性颗粒长大,因而活性中心数量减少,脱硫活性降低.NiMoP催化剂的活性金属含量高,不易被硫代硫酸铵充分硫化,导致预硫化催化剂活性低于对照的NiMoP催化剂.

Ammonium thiosulfate （（NH4）2S2O3） was used as a sulfiding agent for presulfiding CoMo and NiMoP catalysts. The effect of the amount of （NH4）2S2O3 on hydrodesulfurization （HDS） activity was investigated. For the CoMo series, the use of a proper amount of （NH4）2S2O3 gave a higher HDS activity than when the catalyst was sulfided by H2S. SO4^2- formed during presulfidation modified the Al2O3 support and decreased the interaction between the active phase and support, and the activity was enhanced. However, a smaller amount of （NH4）2S2O3 used for the presulfidation would result in insufficient sulfidation, while a larger amount of （NH4）2S2O3 increased the particle size of the active phases, and both were harmful to HDS activity. For the NiMoP series, the presulfided catalysts were less active than those sulfided by H2S. This was ascribed to the high metal content and the addition of P to the catalyst.