Combination and interaction of ammonia synthesis ruthenium catalysts

• Published in: Journal of molecular catalysis. A, Chemical Vol. 259; no. 1; pp. 218 - 222
• Main Authors: Xu, Qing-Chi, Lin, Jing-Dong, Li, Jun, Fu, Xian-Zhu, Yang, Zhen-Wei, Guo, Wei-Ming, Liao, Dai-Wei
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2006; Elsevier
• Subjects: Ammonia synthesis; Carbon nanotubes; Catalysis; Chemistry; Combination-type ruthenium catalyst; Exact sciences and technology; General and physical chemistry; Magnesia; Support–support interaction; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Support–support interaction; Carbon nanotubes; Combination-type ruthenium catalyst; Ammonia synthesis; Magnesia; Mixed catalyst; Ruthenium; Support; Transition metal; Alkali metal; Ammonia; Heterogeneous catalysis; Synthesis; Support-support interaction; Platinoid; Magnesium Oxides; Potassium; Catalyst
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2006.06.030

A novel combination-type ruthenium catalyst has been developed, in which two catalysts, K-Ru/MgO and K-Ru/CNTs, are combined with weight ratio of 1/1. The hightest activity of the combination-type catalyst, K-Ru/CNTs + K-Ru/MgO, reaches 4453   μ mol   N H 3   h − 1   g − cat − 1 at 673 K under 0.2 MPa, which is two times higher than the average activity of the two catalysts. ▪ Based on combination advantages of both supports MgO and carbon nanotubes (CNTs), a novel combination-type catalyst for ammonia synthesis has been developed, in which two catalysts, K-Ru/MgO and K-Ru/CNTs, are combined with the optimal weight ratio of 1/1. The results show that the highest catalytic activity of the combination-type ruthenium catalyst, K-Ru/CNTs + K-Ru/MgO, for ammonia synthesis reaches 4453   μ mol   N H 3   h − 1   g − cat − 1 at 673 K under 0.2 MPa, which is about two times higher than the average activity of the two catalysts under the same operating conditions. It is suggested that there is a complementary interaction between the two supports (CISS), MgO and CNTs, and the combination of both K-MgO and K-CNTs promotes electron transfer from alkali metallic atoms to the B 5-sites of ruthenium.