Supercritical CO2 assisted synthesis of SBA-15 supported amino acid ionic liquid for CO2 cycloaddition under cocatalyst/metal/solvent-free conditions. (December 2022)

• Record Type: Journal Article
• Authors: Qu, Ye; Chen, Yanglin; Ye, Yifei; Xu, Ping; Sun, Jianmin
• Is Part Of: Journal of CO₂ utilization. Volume 66(2022)
• Publication Date: 2022-12
• Subjects: Amino acid ionic liquid -- Supercritical CO2 -- SBA-15 -- CO2 cycloaddition reaction -- Epoxide; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2022.102294
• Languages: English
• ISSNs: 2212-9820

Abstract

Abstract: Heterogenization of homogeneous catalysts without the loss of activity is still a huge challenge. Herein, homogeneous [HTMG][His][I] amino acid ionic liquid (IL), consisting of 1, 1, 3, 3-tetramethylguanidine cation, histidine anion and iodine anion, were introduced into the pore channels of SBA-15 substrate with the assistance of supercritical CO2 (scCO2 ) media. Due to its low viscosity, high diffusivity and absence of surface tension, scCO2 enabled [HTMG][His][I] to highly disperse in SBA-15 pore channels. Surprisingly, [HTMG][His][I]/SBA-15 heterogeneous catalyst displayed higher CO2 cycloaddition activity (95% propylene carbonate yield) than equivalent molar pristine [HTMG][His][I] homogeneous catalyst (69% propylene carbonate yield) under the identical conditions. The significantly enhanced activity was resulted from the synergistic effect of [HTMG][His][I] and SBA-15 support. Moreover, [HTMG][His][I]/SBA-15 performed outstanding universality of various epoxides and reusability. This work developed a promising strategy to heterogenization of homogeneous IL catalyst assisted by scCO2 as synthetic media and provided an efficient catalyst for CO2 conversion. Graphical Abstract: ga1 Highlights: With assistance of scCO2, [HTMG][His][I] was successfully introduced into the pore channels of SBA-15 substrate. The loading amount of [HTMG][His][I] in [HTMG][His][I]/SBA-15 was 3-folds as that synthesized by impregnation method. [HTMG][His][I]/SBA-15 exhibited better CO2 cycloaddition activity than the pristine [HTMG][His][I]. The excellent activity was due to the synergistic effect of [HTMG][His][I] and SBA-15 support. [HTMG][His][I]/SBA-15 performed outstanding universality of various epoxides and reusability.