Effect of Pr and Ce on the activity of Ni2P catalyst prepared by low temperature reduction in hydrodesulphurization
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摘要: 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。Abstract: 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.
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Key words:
- hypophosphites /
- low temperature thermal decomposition /
- Ni2P /
- hydrodesulfurization /
- dibenzothiophene /
- praseodymium /
- cerium
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