Pt-Rh-Pd Alloy Group Gauze Catalysts Used for Ammonia Oxidation

Pt-Rh-Pd alloy gauze catalysts used for ammonia oxidation were studied to improve the efficiency in the industry of nitric acid. According to the character of ammonia oxidation, such catalysts were divided into three main reaction zones. Pt-Rh-Pd alloy group gauzes were installed in dual pressure ammonia oxidation apparatus with the diameter of 3880 mm, which was operated under a pressure of 0.35 MPa. Based on the characterization by FESEM and EDS, the catalysis mechanism of the gauze catalysts was proposed. Through the calculation of oxidation efficiency, the catalysis effect is improved by 1% with the Pt-Rh-Pd alloy gauzes, where the involvement of Pd endows the catalyst with catalysis, catchment, solid solution and second catalysis. As the result, the cost is reduced by 30% and the loss of Pt is decreased from 120 mg to 70 mg. Thus, the catalysts show the great potential for future industrial applications.