Preparation Methods of Ruthenium Catalysts for Ammonia Synthesis

The ruthenium catalysts for ammonia synthesis have higher activity than the iron catalyst, especially under the condition of low temperature and pressure. Different preparation methods and preparation conditions will influence the ruthenium catalyst activity with different support materials. This paper describes the preparation methods of Ru catalysts for ammonia synthesis from three aspects, including the pretreatment of supports, the loading of Ru and the addition of promoters. Different methods such as melting method, sublimation method, ion exchange, ultrasound method, precipitation, sol-gel method, impregnate method, microwave-assisted method are reviewed and the shortages of some methods are discussed. The development trends of the preparation of Ru catalyst are also proposed.