Abstract: In order to effectively mineralize and sequester CO ₂ and improve the fire-fighting effect of coal mines, a method was proposed to synergistically improve the mineralization reaction rate by adding a catalytic CO ₂ conversion substance (triethylenetetramine solution, TETA) and increasing the gas-solid contact area (porous gel). The mass fraction of TETA and initial CO ₂ pressure were determined by single factor tests. The effect of porous gel on CO ₂ mineralization efficiency was studied by means of high temperature and pressure reactor. The mechanism of TETA storage and conversion of CO ₂ was investigated by scanning electron microscopy (SEM) and density functional theory. The results show that the addition of calcium oxide (CaO) can increase the pressure drop of CO ₂ in the reactor, the optimum mass fraction of TETA is from 2.5% to 7.5%, and the initial pressure of CO ₂ is from 0.4 MPa to 0.8 MPa; the mass of the porous gel per unit mass to fix CO ₂ at different temperatures is 0.070 g (20 ℃), 0.077 g (30 ℃) and 0.110 g (40 ℃), respectively.