Cu-Si系环己醇脱氢催化剂中Zn的影响研究

Influence of Zn on Cu-Si based cyclohexanol dehydrogenation catalyst

分析了Cu-Si系和Cu-Zn-Al系环己醇脱氢催化剂在气相环己醇脱氢反应中催化性能存在差异的原因,考察在Cu-Si催化剂中添加Zn对催化剂活性的影响。研究结果表明:在还原态的Cu-Si催化剂中,只存在Cu(0),随着Zn元素的加入,在还原态的Cu-Zn-Si催化剂中出现Cu(0)和Cu(+),且随着Zn含量的增加,Cu(+)含量随之增加;结合活性检测结果,Cu(+)的存在提高了环己醇的转化率,但随着Cu(+)含量增多,也会导致脱氢副反应增多,进而降低环己酮的选择性。

The reason for the difference of catalytic performance between Cu-Si and Cu-Zn-Al cyclohexanol dehydrogenation catalyst in vapor-phase cyclohexanol dehydrogenation reaction is analyzed.The effect of adding Zn to Cu-Si catalyst on the catalyst activity is investigated.The results show that only Cu^(0) exists in the reduced Cu-Si catalyst.With the addition of Zn,Cu^(0) and Cu^(+)appear in the reduced Cu-Zn-Si catalyst,and the content of Cu^(+)increases with the increase of Zn content.Combined with the activity test results,the presence of Cu^(+)improves the conversion of cyclohexanol,but with the increase of Cu^(+)content,it will also lead to the increase of dehydrogenation side reactions,thus reducing the selectivity of cyclohexanone.