新型高效双功能铁催化剂催化CO2转化研究

Highly efficient new bifunctional iron catalysts for the conversion of CO2

合成了一系列含有季膦、季铵基团的双功能希夫碱铁(Ⅲ)催化剂,运用红外、紫外、核磁、元素分析、质谱等现代分析技术对其结构进行了表征,系统地探讨了反应温度、CO2压力、反应时间、催化剂负载量和不同取代基对配体的影响,还研究了该催化剂对其它环氧烷的适用性,并提出了可能的催化机理.结果表明:这些双功能希夫碱铁配合物在无任何助剂和溶剂的条件下,可以高效、高选择性(>99%)地催化与CO2和环氧烷的偶联反应生成环状碳酸酯.最佳优化反应条件为:70℃、3 MPa、5 h、催化剂2A:PO摩尔比为1:100.

In present work, a series of bifunctional salenFe(Ⅲ) catalysts containing quaternary phosphine or quaternary ammonium groups were synthesized. They were characterized by FTIR, UV, NMR, elemental analysis and MS. The effects of reaction temperature, CO2 pressure, reaction time, catalyst loading and different substituents on the ligand were investigated systematically. In addition, the applicability of the catalyst to other alkylene oxides was also studied, and the possible reaction mechanisms were proposed. The results indicated that the bifunctional salenFe(Ⅲ) catalysts had high catalytic activity for the cyclic carbonate synthesis from CO2 and epoxides with excellent yields and high selectivity(>99%) in the absence of any solvents or co-catalysts. The optimal reaction conditions were determined as follows: 70 ℃, 3 MPa, 5 h, catalyst 2 A:PO mole ratio of 1:100.