助剂对活性炭负载钴催化剂氨合成活性的影响

Effects of promoters on the activity of activated carbon supported cobalt catalysts for ammonia synthesis

采用四槽高压连续流动反应器研究了添加助剂Ba、K和Sm对活性炭负载钴催化剂氨合成活性的影响,结果发现,添加助剂Ba、K和Sm可以提高催化剂的氨合成活性,其中,Ba的促进效果最好,Ba与Co物质的量比为0.3时,催化活性最高。在Ba-Co/AC催化剂中,助剂Sm的加入降低了催化剂的氨合成活性,而少量K助剂(K与Co物质的量比为0.25～0.5)可以提高其催化性能,在10 MPa、10 000 h^(-1)和450 ℃条件下,双助剂催化剂的氨合成活性可达120 mmol·(g·h)^(-1),进一步增加K的量,其氨合成活性下降。

The influence of promoters on the activity of activated carbon supported cobalt catalysts for ammonia synthesis was studied. The results showed that the presence of promoters such as Ba, K and Sm led to enhanced ammonia synthesis aetivity; Ba was the best promoters for Co/AC catalyst, with the optimal activity at Ba/Co molar ratio of 0.3. Addition of Sm led to decline activity of Ba-Co/AC catalyst, while a little content of potassium （ K/Co molar ratio of 0.25 - 0. 5 ） improved activity of Ba-Co/AC catalyst. Ammonia synthesis activity of over 120 mmol · （g · h）^-1 was obtained over Ba-K-Co/AC catalyst under 10 MPa, 10 000 h^-1 and 450℃.