双重孔分布氧化铝载体及加氢脱金属催化剂结构与性质研究

Study on the structure and properties of alumina support with double pore distribution and hydrodemetallization catalyst

关键词:  双重孔  氧化铝  载体  加氢脱金属催化剂  结构  性质

Key words:  double pore  alumina  support  hydrodemetallization catalyst  structure  property

摘要:

对含有微米级孔道γ-Al₂O₃载体进行碳酸氢铵水热改性处理,制备双重孔分布氧化铝载体,并以该氧化铝为载体制备加氢脱金属催化剂,应用SEM、N₂吸附-脱附、TPR、Raman、原位CO吸附等技术表征氧化铝载体及加氢脱金属催化剂的结构与性质。实验结果表明,改性处理后,γ-Al₂O₃载体表面及微米级孔道中交织生长微米级棒状结构γ-Al₂O₃粒子,使氧化铝载体具有集中的10～15 nm孔道分布和适宜的1～2 μm孔道含量。与未改性氧化铝载体相比,以改性处理后的氧化铝为载体制备的加氢脱金属催化剂的程序还原峰温降低,催化剂中八面体钼的相对含量和Ni-Mo-S活性位数量增加,加氢脱金属活性和加氢脱氮活性明显提高。 

Abstract:

Gamma-alumina support with micron-sized porous was hydrothermally modified with ammonium bicarbonate solution to prepare the alumina support with double pore distribution, and the alumina was used as the support to prepare the hydrodemetallization catalyst. The structure and properties of the alumina support and the hydrodemetallization catalyst were analyzed by SEM, N₂ adsorption-desorption, TPR, in situ CO adsorption techniques. It was found that after hydrothermal modification, a large number of micron rod-like particles were formed on the surface of alumina support and in micron-sized channels, and the alumina support has a concentrated 10-15 nm channel distribution and a suitable 1-2 μm channel content. Compared with unmodified alumina support, the peak temperature of programmed reduction of the hydrodemetallization catalyst was decreased, the relative content of octahedral molybdenum and the Ni-Mo-S activity number were increased, the hydrodemetallization activity and hydrodenitrification activity were improved obviously.