水热改性对NiMo/γ-Al2O3加氢脱氮催化剂结构及性能的影响

The influence of hydrothermal modification on the structure and hydrodenitrogenation (HDN) activity of NiMo/γ-Al₂O₃catalyst was studied in the range 140～180 ℃. The experimental results indicated that the hydrodenitrogenation reaction rate of pyridine was accelerated using the NiMo/γ-Al₂O₃catalyst synthesized via hydrothermal route due to the change of the structure, the increase of the amount of Mo and Ni and the rise of the specific surface area. The change of the structure of catalysts was enhanced at higher hydrothermal temperature, producing NiMo/γ-Al₂O₃catalyst with better HDN activity.     

水热改性对氧化铝载体织构和表面性质的影响

The alumina support was treated in the moderate aqueous hydrothermal condition to avoid from the excess growth of boehmite (AlOOH) crystals which usually results in the obvious decrease of the specific surface area (BET). The experimental results indicated that the hydrothermal treatment of the alumina support at 140 ℃ for 2 hours promoted the formation of the plate-like AlOOH crystallites on the surface of the support via dissolution-precipitation route. The occurrence of the nano plate-like structure led to the improvement in the structural and surface properties, such as the increase of the specific surface area, the surface hydroxyl concentration and the surface acidity.