S. Podila, H. Driss, Y.A. Alhamed, A. Al-Zahrani, L.A. Petrov
King Abdulaziz University, Saudi Arabia
pp. 139 - 142
Keywords: ammonia decomposition, hydrogen generation, cobalt catalysts, Mf/La mixed oxides
Generation of COx free hydrogen by ammonia decomposition (AD) is more attractive from practical and economical perspectives compared to other process. Previous studies showed that Ru supported on multi wall carbon nanotubes (MWCNTs) is the most active catalyst. Unfortunately MWCNTs as a support suffered from high cost, methanation of carbon at high temperatures and low metal support interaction. Therefore, developing of a cheap and affordable active catalyst for AD is highly desirable. In this investigation Mg/La mixed oxide support (Mg/La = 3) were prepared by co-precipitation from Mg and La nitrates solutions under super saturation conditions followed by calcination at 450 oC in in either N2, air or vacuum followed by impregnation with 5 wt.% Co. Activity measurements for AD showed that the catalyst for which the support was calcined in nitrogen are the most active. This catalysts also showed stronger metal support interaction as indicated by TPR measurements. SEM micrographs also showed that in this catalyst the formation Mg/La mixed oxide phase is more prominent compared with air calcined supports. Hence formation of Mg/La mixed oxide in N2 atmosphere might be a major contributor to the higher activity of these catalysts.