改性铜基催化剂催化乙炔氢氯化反应的研究

Acetylene hydrochlorination reaction catalyzed by modified copper-based catalyst

利用浸渍法将2,5-二甲基吡嗪(DMP)和氯化铜负载到活性炭上,在140℃、乙炔体积空速为50 h-1、氯化氢与乙炔摩尔比为1.05∶1的条件下,测试了其对乙炔氢氯化反应的催化性能。利用ICP-AES、红外光谱、XRD和TG等手段对催化剂进行表征。结果表明,加入2,5-二甲基吡嗪后,Cu表观质量分数为17%的催化剂的乙炔转化率可达74.02%,氯乙烯选择性可达97.19%。2,5-二甲基吡嗪提高铜基催化剂活性的原因在于其可以减少铜物种聚集,提高活性组分的分散度;可以产生Cu-N配位化学键,锚定铜物种使其稳定;可以抑制催化剂积碳,减少积碳引起的失活现象。

2,5-Dimethylpyrazine(DMP)and copper chloride are both loaded onto activated carbon through using impregnation method,and used as the catalyst in the acetylene hydrochlorination reaction.The catalytic performance of the catalyst is tested at 140℃,with an acetylene volume space velocity of 50 h-1 and a hydrogen chloride to acetylene molar ratio of 1.05:1.The catalyst is characterized by means of ICP-AES,infrared spectroscopy,XRD,and TG methods.The results show that the conversion rate of acetylene achieves 74.02%and the selectivity of vinyl chloride reaches 97.19%over the catalyst with an apparent Cu content of 17%after adding 2,5-dimethylpyrazine.The improvement of the activity of copper-based catalyst by 2,5-dimethylpyrazine can be attributed to that 2,5-dimethylpyrazine can reduce the aggregation of copper species and improve the dispersity of active components,which can generate Cu-N coordination chemistry bond,anchoring copper species to make it stable.2,5-Dimethylpyrazine can suppress carbon deposition on the surface of the catalyst and reduce deactivation caused by carbon deposition.