Mixed matrix membrane (MMM) and method of H2/CO2 gas separation by using MMM

A method for separating a hydrogen/carbon dioxide mixed gas, comprising:

• using a mixed matrix membrane to separate the hydrogen/carbon dioxide mixed gas at a temperature from 10° C. to 40° C. to allow hydrogen preferentially penetrate through the mixed matrix membrane to separate the hydrogen from the carbon dioxide,
• wherein a pressure at a feed side of the mixed matrix membrane ranges from 0.1 bar to 5 bar;
• a molar ratio of the hydrogen to the carbon dioxide is 1:1 and a corresponding partial pressure of each of the hydrogen and the carbon dioxide ranges from 0.05 bar to 2.5 bar;
• wherein the mixed matrix membrane comprises a polymer matrix and an M(SiF6)(pyz)3 nanoparticle dispersed in the polymer matrix, wherein M is selected from the group consisting of Cu, Zn, Co, and Ni, pyz is pyrazine;
• and
• the mixed matrix membrane is prepared by the following steps;
• step 1:
• dissolving the polymer matrix in water to obtain a matrix solution, and dissolving an MSiF6 metal salt in water to obtain a salt solution;
• step 2:
• mixing the matrix solution and the salt solution in a mass ratio to obtain a coating solution, coating the coating solution on a carrier, and conducting evaporation to remove a solvent, wherein during the mixing, a mass of the MSiF6 metal salt is 9% to 91% of a total mass of the metal salt and the polymer matrix;
• and
• step 3:
• placing the carrier obtained in the step 2 in a ligand vapor to allow a reaction to obtain the mixed matrix membrane, wherein the ligand vapor is pyrazine.