Abstract
Abstract Promoter effects of alkali metal nitrates and alkali earth metal nitrates on Ru/A.C. (active carbon) were studied in order to prepare an effective catalyst for ammonia synthesis. Of alkali metal nitrates, RbNO3 was more effective than CsNO3 and KNO3. Alkali earth metal (Mg, Ca, Sr, Ba) nitrates were also found to be effective promoters on Ru/A.C. catalysts. Of them heavier alkali earth metal elements were more effective (Ba>Sr>Ca>Mg). Ba(NO3)2 was as effective as CSNO3, which was not expected from the stand point of electronegativity. The transformation of promoter precursors to active compounds (nitrates to oxides or hydroxides) and the interaction of promoters and ruthenium were discussed. Precursor of ruthenium salt was also studied. RuCl3·3H2O and [Ru(NH3)6]Cl3 gave higher activities than Ru3(CO)12. It was discussed that RuCl3 gave finer Ru particles than Ru3(CO)12 on active carbon. The turn over frequency (TOF) of Ru–Rb+/A.C. was lower than those of RU–Cs+/Al2O3 and of Ru–Cs+/MgO.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
