Influence of Ethylene Diamine Tetraacetic Acid on the Performance of Magnesia Supported Ru-based Catalysts for Ammonia Synthe

Abstract:

A series of barium doped nano-magnesia supports (Ba-MgO) modified with EDTA were prepared by chemical co-precipitation with ultrasonic method and were used as supports to prepare Ru-based catalysts. The surface texture and the matter phase of the supports and Ru catalysts were characterized by X-ray diffraction, scanning electron microscope, N2 physical-adsorption, H2 temperature-programmed reduction and inductively coupled plasma-atomic emission spectrometry respectively. The results showed that modification of EDTA increased the amount of barium promoter into the support and controlled the formation state of barium in support. The effects of barium promoter content and surface texture in support achieved an equilibrium state when the molar ratio of EDTA to Ba was 1/2, and the highest activity of Ru/Ba-MgO catalyst was 69.31 mmol g-1h-1 under the reaction conditions of 10 MPa, 10 000 h-1 and 698 K.