以Fe/活性炭为催化剂由甲烷和氮气合成氨

Ammonia Synthesis from Methane and Nitrogen over AC-supported Fe Catalyst

采用浸渍法制备了活性炭担载的Fe基催化剂。利用N2物理吸附、X射线粉末衍射、氢气程序升温还原等方法对载体和催化剂进行了表征。以甲烷和氮气为原料,在自制的常压连续流动式反应器中进行了直接合成氨实验。结果表明,在600～800℃之间有氨气产生,同时有乙烯、乙烷等物质生成,并且甲烷的转化速率和氨的生成速率随温度的升高而增大;在700℃时,甲烷的转化速率为6.9×10-7mol.g-1.s-1,氨的生成速率为1.264×10-8mol.g-1.s-1。甲烷的转化率以及氨生成速率随甲烷与氮气的摩尔比不同而不同,本实验条件下甲烷-氮气合成氨的合适摩尔比为CH4∶N2=9∶1。

The iron catalyst supported on activated carbon was prepared by the impregnation method.N2 physisorption,X-ray diffraction and H2 temperature programmed reduction were carried out to characterize the supports and iron catalyst.The ammonia synthesis was tested in a home-built continuous-flow reactor with methane and nitrogen as the feed gases.It was proved that NH3,ethene,ethane and some other substances were produced at 600 ～ 800℃,and methane conversion rate and ammonia production rate increased as raising temperature.At 700℃,methane conversion rate was 6.9 × 10-7 mol.g-1.s-1;ammonia production rate was 1.264 × 10-8 mol.g-1.s-1.The results also indicated that methane conversion and ammonia production rate were varied by ratios of CH4 and N2 t,he optimal ratio of them for ammonia synthesis was CH4 ∶ N2 = 9∶ 1 under the as-experimental conditions.