Effect of barium and potassium promoter on Co/CeO2 catalysts in ammonia synthesis

The Co/CeO2 catalysts promoted with Ba or K were prepared to study the effect of promoter on the catalytic performance of ammonia synthesis. The results show that the presence of Ba or K promoter changes the properties of CeO2-supported Co catalysts including the surface area, the crystallite size and the morphology of CeO2, the reduction degree of cobalt species and the adsorption performance of hydrogen and nitrogen. As a consequence, the samples promoted with an appropriate amount of Ba show higher ammonia synthesis rates, while the catalysts with high Ba loading or K promoter all exhibit low catalytic activities. (C) 2018 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.

制备了Ba或K促进的Co/CeO₂催化剂，以研究助剂对氨合成催化性能的影响。结果表明，Ba或K助剂的存在改变了CeO₂负载的Co催化剂的性能，包括CeO₂的表面积、晶粒尺寸和形貌、钴物种的还原程度以及氢和氮的吸附性能。因此，适量Ba促进的样品显示出较高的氨合成速率，而高Ba负载量或含K助剂的催化剂都表现出较低的催化活性。(C) 2018中国稀土学会。由爱思唯尔出版集团出版。保留所有权利。