CO

1. A CO 2 -facilitated transport membrane, comprising:

a hydrophilic porous membrane having a heat resistance of 100° C. or higher; and

a gel layer formed from a polyvinyl alcohol-polyacrylic acid copolymer gel membrane containing moisture, which contains at least one of cesium carbonate and cesium bicarbonate and cesium hydroxide therein as an additive, the gel layer being supported on the hydrophilic porous membrane; wherein the gel membrane has CO 2 /H 2 selectivity under a temperature condition of 100° C. or higher, and wherein the gel layer is formed such that a weight ratio of cesium carbonate relative to a total weight of the polyvinyl alcohol-polyacrylic acid copolymer gel membrane and cesium carbonate is 65% by weight or more and 85% by weight or less.

2. A method for removing CO 2 , the method comprising:

bringing a CO 2 -facilitated transport membrane into contact with a gas containing CO 2 at 100° C. or higher, the membrane having a CO 2 /H 2 selectivity at 100° C. or higher, thereby removing the CO 2 from the gas, wherein:

the CO 2 -facilitated transport membrane is formed such that a gel layer is supported by a hydrophilic porous membrane, and the gel layer is obtained by adding at least one of cesium carbonate and cesium bicarbonate and cesium hydroxide or at least one of rubidium carbonate and rubidium bicarbonate and rubidium hydroxide to a gel membrane containing moisture.

3. The method for removing CO 2 according to claim 2 , wherein the gel membrane containing moisture is a polyvinyl alcohol-polyacrylic acid copolymer gel membrane.