Supported ionic liquid (IL) sorbents for CO₂ capture were prepared by impregnating tetramethylammonium glycinate ([N₁₁₁₁][Gly]) into four types of porous materials in this study. The CO₂ adsorption behavior was investigated in a thermogravimetric analyzer (TGA). Among them, poly(methyl methacrylate) (PMMA)-[N₁₁₁₁][Gly] exhibits the best CO₂ adsorption properties in terms of adsorption capacity and rate. The CO₂ adsorption capacity reaches up to 2.14 mmol·g^{− 1} sorbent at 35 °C. The fast CO₂ adsorption rate of PMMA-[N₁₁₁₁][Gly] allows 60 min of adsorption equilibrium time at 35 °C and much shorter time of 4 min is achieved at 75 °C. Further, Avrami's fractional-order kinetic model was used and fitted well with the experiment data, which shows good consistency between experimental results and theoretical model. In addition, PMMA-[N₁₁₁₁][Gly] remained excellent durability in the continuous adsorption–desorption cycling test. Therefore, this stable PMMA-[N₁₁₁₁][Gly] sorbent has great potential to be used for fast CO₂ adsorption from flue-gas.