Effect of ceria morphology on the catalytic activity of Co/CeO2 catalyst for ammonia synthesis

A series of Co/CeO2 catalysts with different morphology of CeO2 support were prepared. It was shown that part of Co species could be introduced into the CeO2 lattice and thus a new Co-O bonding would be created for the ceria-supported Co catalysts. The morphology of CeO2 was found to affect the reduction of both the cobalt oxides and CeO2. A larger amount of CeO2 was reduced in the case of Co supported on polyhedral CeO2. Catalytic tests showed that the higher concentration of Ce3+ and the lower binding energy of Co species present in the catalyst are key factors that led to higher ammonia synthesis rates for the Co/CeO2 catalysts.