镨和铈对低温还原法制备的Ni2P催化剂加氢脱硫活性的影响

采用低温热解次磷酸盐法制备了Ni₂P-L、Pr-Ni₂P-L和Ce-Ni₂P-L催化剂,并采用XRD、H₂-TPR、BET、CO吸附、XPS等手段对制备得到的催化剂进行了表征。以二苯并噻吩(DBT)为模型化合物,研究了Pr、Ce稀土元素对低温还原法制备的Ni₂P-L催化剂加氢脱硫(HDS)性能的影响。结果表明,催化剂添加稀土Pr和Ce能够抑制Ni₅P₄和其他杂晶的生成,从而促进活性相Ni₂P的生成;添加稀土能提高催化剂对联苯(BP)的选择性,但催化剂的总HDS活性略有降低。

Effect of Pr and Ce on the activity of Ni2 P catalyst prepared by low temperature reduction in hydrodesulphurization

The Ni₂P-L, Pr-Ni₂P-L and Ce-Ni₂P-L catalysts were prepared by thermal decomposition of hypophosphites and reduced at low temperature; they were characterized by X-ray diffraction (XRD), temperature programmed reduction with hydrogen (H₂-TPR), nitrogen physisorption, CO adsorption, and X-ray photoelectron spectroscopy (XPS). The effect of the rare earth praseodymium (Pr) or cerium (Ce) elements on the activity of Ni₂P-L catalyst in hydrodesulfurization (HDS) was investigated with dibenzothiophene (DBT) as a model compound. The results indicated that the addition of Pr and Ce can suppress the formation of Ni₅P₄ and other mixed crystal phases and then promote the formation of Ni₂P phase. After adding the rare earth metals, the selectivity to BP over the Ni₂P catalyst is enhanced greatly, though the total HDS activity is decreased slightly.