Preparation And Research Of Ammonia Synthesis Over Ruthenium Catalyst Supported On ABO₃ Perovskite -type Oxides

Artificial nitrogen have a significant impact on agriculture and industry, and the ammonia synthesis is known as a never-ending task. Industrial ammonia synthesis exist too large energy consumption that become a big bottleneck to hinder its development, research of new type ammonia synthesis catalyst not only has profound realistic significance for industrial energy saving, but also for the whole catalytic science development is of great theoretical significance. This paper respectively prepared cerium base perovskite, different alkaline earth metal titanium base perovskite and Y doped BaZrO3 as the carrier of ruthenium based ammonia synthesis catalyst, and through modern catalytic characterization techniques XRD, N2 physical adsorption, H2-TPR, H2-TPD, CO2-TPD and O2-TPD, HRTEM reveals the perovskite oxides such as load highly reactive mechanism of ruthenium ammonia synthesis catalyst, the results are as follows:Compared with catalyst MgCeO3, CaCeO3, SrCeO3, BaCeO3, the activity of the catalyst order is Ru/MgCeO3> Ru/CaCeO3> Ru/SrCeO3> Ru/BaCeO3. Through analysis the characterization results, MgCeO3 carrier material has larger specific surface area, high dispersion of Ru, thus it can improve the load activity of ruthenium ammonia synthesis catalyst.Alkaline earth metal load of titanium base of perovskite composite oxides Ru promote order of ammonia synthesis catalyst for Ba> Sr> Ca. XTiO3 (X= Ca, Sr and Ba)A bit of alkaline earth metal elements in different carriers can affect the intensity of alkaline, H2 adsorption on the surface of the catalyst, and the strength of the interaction between the carrier and the metal, they can affect the activity of catalysts. XTiO3 in load system of Ru Ru/BaTiO3 highly active mainly due to the strong catalyst carrier for electronic ability and strong inhibition of H2.Study carrier roasting temperature, Y amount doped and Ru load for Ru/BaZr1-xYxO3-δ affect the structure and properties of the ammonia synthesis catalyst. Different calcination temperature have the influence on the carrier material and texture properties of ammonia synthesis activity, the size of the order:BZY-1000> BZY-900>> BZY-800 BZY-700> BZY-1100; Y doped content under different conditions, Ru/BaZrO3 ammonia synthesis catalyst activity size order:BZY-10%> BZY-15%> BZY-20%> BZY-5%; Different Ru doped content, Ru/BaZrO3 ammonia synthesis catalyst activity size order:BZY-2% Ru> BZY-3% Ru> BZY-4% Ru> Ru BZY-1%. The optimized preparation conditions are determined by way of contrast experiment is:Y doping amount was 10%, the carrier calcination temperature is 1000℃, Ru load of 2%.Domestic and foreign scientific research units have confirmed that the ruthenium perovskite oxide carrier load under the condition of low temperature and low pressure can be showed excellent activity of ammonia synthesis, so the system not only has important theoretical significance and certain industrial application value.