Enhancement of Ammonia Synthesis on a Co3Mo3N-Ag Electrocatalyst in a K-βAl2O3 Solid Electrolyte Cell

The electrochemical promotion of ammonia synthesis by potassium ions (K+) on a Co3Mo3N-Ag electrocatalyst was studied in a K-beta ''-Al2O3 solid electrolyte cell. The effect of temperature (400-550 degrees C), P-H2/P-N2, feed composition (1.0, 3.0 and 6.0) and applied voltage was explored in detail. The catalyst was prepared by ammonolysis of the mixed oxide and was characterized by XRD and SEM. A volcano-type behavior was found, i.e., around 1% of potassium per total moles of Co3Mo3N improved the ammonia formation rate by as much as 48%. However, high percentages of potassium act as poison for the reaction, possibly due to the formation of K-N-H compounds that block the active sites. Faradaic efficiency (Lambda) values close to 300 are for the first time reported in NH3 synthesis.