2.1 Materials
CO2 (99.99 mol%) was purchased from Nanjing Chuangda
Gas Co., Ltd, China. Tetraethylammonium hydroxide
([N2222][OH], 25 wt% in methanol),
Tetramethylammonium hydroxide ([N1111][OH], 25
wt% in methanol), malononitrile
(CH2(CN)2, 99 wt%), and methanol (99.5
wt%) were supplied from Aladdin Chemical Reagent Co., Ltd. Ethylene
glycol, (EG, 99 wt%), imidazole (Im, 99 wt%), 1-Ethylimidazole (Eim,
99 wt%), dimethyl2-(2-aminoethoxy)ethanol (DMEE, 99wt%),
Tetramethylene sulfone (SUL, 99 wt%),were purchased from Shanghai
Macklin Biochemical Co., Ltd. All the chemicals were used directly
without further purification.