氮改性对乙炔氢氯化反应催化剂吸附性能的影响

Effect of N-modification on the Adsorption Performance of Acetylene Hydrochlorination Catalyst

基于密度泛函理论计算方法,对乙炔氢氯化反应中的催化剂AuCl3二聚体和碳载体分别进行了氮改性,并对其改性前、后的分子分别进行建模优化,比较其分子空间结构的变化,以及对HCl、C2H2、C2H3Cl的吸附能的影响。实验结果表明:氮改性后的AuCl3二聚体与乙二胺的络合物与改性前的AuCl3二聚体相比,Au3+离子之间的距离从3.627增至5.446;对HCl的吸附能从-3.241kJ/mol增至22.926kJ/mol,对C2H2、C2H3Cl的吸附能影响不大。氮改性后的碳载体与改性前相比,对HCl的吸附能从6.898kJ/mol增至9.615kJ/mol,对C2H2、C2H3Cl的吸附能影响较小。计算结果表明:改性后的AuCl3二聚体与乙二胺的络合物和碳载体,可降低催化剂发生团聚的可能性,延长了其使用寿命。

Based on density functional theory（DFT）,the catalyst AuCla dimer and carbon carrier of acetylene hydrochlorination reaction and their nitrogen-modified molecules were conducted for modeling optimization, respectively, and compared the molecular changes in the structure of space and the adsorption energy on HC1,Ce He ,C2 H3 C1. Results showed that,compared with the AuCl3 dimer, the distance between Aua＋ ion of the nitrogen-modified AuCla dimer with ethylenediamine complexes increased from 3. 627A to 5. 446A; the adsorp tion energy of the nitrogen-modified AuCl3 dimer with ethylenediamine complexes on HC1 increased from -- 3. 241 kJ/mol to 22. 926 kJ/mol, and it had little effect on C2 H2 and C2 Ha CI. The nitrogen-modified carbon carrier was more conducive to increase the adsorption on HCl（from 6. 898 kJ/mol to 9. 615 kJ/mol）. The calculation results showed that AuCl3 dimer modified with ethylenediamine complex and the nitrogen-modified carbon carrier with could reduce the possibility of catalyst reunion and prolong its life.