No abstract

The high viscosity of ionic liquids (ILs) limits their practical application in SO2 capture. In this work, the low viscous aminoalkyl‐phenyl‐silanes were synthesized to capture SO2. The π–π interaction between phenyl groups reduced the volatility of aminoalkyl‐phenyl‐silanes greatly, but it did not increase their viscosity significantly. Among them, N‐[(dimethylphenylsilyl)methyl]‐N‐methylbenzenemethanamine (DPSA) containing two phenyl groups exhibited the strongest π–π interaction. Therefore, the thermal decomposition temperature reached 150°C, while its viscosity was only 8.45 mPa·s at 25°C, which is much lower than that of ILs. The absorption enthalpy and entropy change of DPSA absorption reaction were −79.284 kJ/mol and −224 J/mol/K, respectively. These values are more negative than those of SO2 capture reaction with ILs. An objective function was proposed to obtain the optimal absorption and desorption temperature. Furthermore, five cycles of regeneration experiments indicated that DPSA possessed good regeneration ability.