Cs-Promoted ruthenium catalyst supported on Ba5Ta4O15 with abundant oxygen vacancies for ammonia synthesis

Green synthesis of ammonia from steam and air using solid oxide electrolysis cells composed of ruthenium‐modified perovskite catalyst

“…More active sites allowed for the N 2 adsorption at the B‐site of the perovskite and activation on the desorption surface of the cathode 32,33 . At the same time, the Ru element's exsolution formed numerous oxygen vacancies in ex‐ LSCrFRu 1.0 h, which can also enhance the adsorption and activation of N 2 , further improving the ammonia synthesis 34 . In addition, more oxygen vacancy generation also facilitated the ORR process by generating more O 2− through an H 2 O splitting reaction (Equation ) on the surface of ex‐ LSCrFRu 1.0 h than on the LSCrF catalyst (Figure ).…”

“…32,33 At the same time, the Ru element's exsolution formed numerous oxygen vacancies in ex-LSCrFRu 1.0 h, which can also enhance the adsorption and activation of N 2 , further improving the ammonia synthesis. 34 In addition, more oxygen vacancy generation also facilitated the ORR process by generating more O 2− through an H 2 O splitting reaction (Equation S4) on the surface of ex-LSCrFRu 1.0 h than on the LSCrF catalyst (Figure S9). Correspondingly, more H + was provided for hydrogenation-reaction, improving the ammonia synthesis.…”

Regulating oxygen vacancies by Zn atom doping to anchor and disperse promoter Ba on MgO support to improve Ru-based catalysts activity for ammonia synthesis

“…Therefore, the supported Ru catalyst is considered as the second generation ammonia synthesis catalyst. [5][6][7][8][9] Various materials, including nitrides, 10,11 perovskites, 12 carbon, 13,14 and metal oxides 15,16 have been developed as supports. Among these, MgO, due to its low cost, stability, and strong electron donating ability, is widely regarded as a promising support for Ru-based ammonia synthesis catalysts; and the alkaline earth metal Ba is one of the most effective promoters in Ru/MgO ammonia synthesis catalyst systems.…”

“…Oxygen vacancy (OVs), a type of surface defect, have effects on the stability of the support, 30 and change the acid-base site on the support surface to promote H 2 adsorption. 31,32 Furthermore, OVs facilitate electrons transfer from OVs to nitrogen molecules adsorbed on Ru nanoparticles (Ru NPs), which enhances the electron-donating capacity of Ru and promotes the dissociation of N N. 12,33 Atom doping, a prevalent technique for generating OVs, 34 involves the substitution of original metal cations with other metal atoms within the metal oxide support, thereby promoting the generation of OVs. 35 …”

Co nanoparticles supported on mixed magnesium–lanthanum oxides: effect of calcium and barium addition on ammonia synthesis catalyst performance

“…Among them, alkali and alkaline earth metals are the most commonly reported in the literature. [18][19][20][21][22][23][24][25][26][27][28] However, it is essential that the effect of a promoter is also related to the support. For the carbon-supported ruthenium catalysts, among the alkali earth metals, the heavier elements were more effective (Ba > Sr > Ca > Mg).…”