Effects of solvent stabilizer in the preparation of highly active potassium-promoted Ru/MgO catalysts for ammonia synthesis

A method for the preparation of highly active potassium-promoted Ru/MgO catalyst (K–Ru/MgO-a(Eg)) has been designed. Ethylene glycol was used as reducing agent for the reduction of RuCl3 at 433 K, simultaneously, as a solvent stabilizer for the size of ruthenium nanoparticles and the morphology of MgO. In the process of impregnating promoter, KNO3 was used as promoter precursor and the ethylene glycol protected ruthenium nanoparticles from agglomeration. The ruthenium particle size of the K–Ru/MgO-a(Eg) was in the range of 1.5–2.8 nm. The highest activity of the nano-catalyst was 6342μmolh-1g-cat-1 under 0.2 MPa at 658 K.