Ambient pressure ammonia decomposition using Ga-Co supported catalytically active liquid metal solutions

Ga-Co supported catalytically active metal solutions (SCALMS) on silicon carbide (SiC) were successfully tested for ambient pressure ammonia decomposition in the temperature range between 480 and 580 °C. Comparison studies of a Ga₅₉Co SCALMS system with their monometallic equivalents Co/SiC and Ga/SiC revealed a massively enhanced ammonia decomposition activity of the supported alloy catalyst. The Ga₅₉Co/SiC outperformed a monometallic benchmark Co/SiC catalyst in terms of the Co specific H₂ productivity by up to one order of magnitude. Monometallic Ga/SiC, in contrast, showed no activity for ammonia decomposition up to 580 °C. We report productivities of 487 g_H2 g_Co ^-1 h^-1 at 5% conversion and 550 °C at a weight hourly space velocity (WHSV) of 29 000 mL_N g_cat ^-1 h^-1 for our SCALMS system. Apparent activation energies (E _A,app) determined from temperature variation experiments give no indication for diffusion limitations under the applied reaction conditions. Therefore, we present a new catalyst material concept for ammonia decomposition with high potential for practical and technical application.