Effects of Stearic Acid Modification on Ru-Ba-MgO Interaction and the Underlying Mechanism

In this paper, a series of Ru/Ba-MgO-SAx catalysts modified with different stearic acid (SA) contents were prepared by ultrasonic-strong electrostatic adsorption (SEA) method. X-ray diffractometer, field emission scanning electron microscope, Fourier- transformed infrared spectrometry, temperature-programmed reduction and other methods were used to characterize the Ba-MgO-SAx and its supported ruthenium-based catalyst. The results show that the addition of SA significantly improves the surface morphology and texture parameters of Ba-MgO support, changes the single adsorption type of Ba2+ in solution, effectively promotes the addition of promoter Ba, and is also beneficial to the regulation of Ru particles and their dispersion, enhances the interaction between the Ba-MgO and Ru, thereby improving the catalytic activity of ammonia synthesis. When the addition amount of SA is 4 wt%, the catalytic activity is the best, and its outlet ammonia concentration is 16.06 % under the reaction conditions of 450 degrees C, 10 MPa and 10000 h(-1).