活性炭对钌基氨合成催化剂活性的影响

Study on ruthenium ammonia synthesis catalyst supported on carbon

研究了不同活性炭的表面性质与钌基氨合成催化剂活性的关系。以不同种类的活性炭为载体制备的钌基催化剂,其活性有很大的不同。活性炭的表面结构和表面化学性质均会对催化剂性能产生重要影响。研究发现催化剂活性与活性炭比表面积,总孔容之间并没有直接的依赖关系,而活性炭载体的灰分,pH值及中孔的孔容对催化剂活性影响较大。对活性炭进行适当的氧化改性处理可以提高催化剂的活性。促进剂与载体及活性组分之间存在强相互作用,当促进剂的含量改变时钌基催化剂的活性也产生明显变化,并且研究表明适当增大助剂K的含量可以提高催化剂的低温活性。

The effects of the surface characteristics of different activated carbons on the catalytic activities of ruthenium catalysts for ammonia synthesis were studied. The activities of the catalysts differ greatly when the catalysts support on different activated carbons. The results show that the effect of the surface physical and chemical characteristics of activated carbon on the activities of catalysts is significant. There is no direct relationship between catalyst activities, the surface area, and the total pore volume of activated carbon; but the ash content, pH value and meso-pore volume influence the activity obviously. Proper oxidation treatment of activated carbons can improve the activity. We also found that there was a strong interaction among the promoter, the support and the ruthenium. When we changed the promoter quantities, the activities of the catalysts were affected clearly.Study showed proper increase K content can improve the catalyst's low temperature activity.