Cathode electrode for gas diffusion electrolytic flow cell, and gas diffusion electrolytic flow cell

1 . A cathode electrode for a gas diffusion electrolytic flow cell that produces a carbon dioxide reduction product by reducing carbon dioxide gas, wherein

the cathode electrode comprises a catalyst layer having a metal complex catalyst, a carbon material and a solid alkali metal salt, and a gas diffusion layer disposed on the catalyst layer,

wherein the alkali metal salt in the catalyst layer exists in a solid state even during the reduction of carbon dioxide.

2 . The cathode electrode for the gas diffusion electrolytic flow cell according to claim 1 , wherein the alkali metal salt comprises a potassium salt.

3 . The cathode according to claim 1 , wherein the metal complex catalyst is selected from the group consisting of the following formulae (1), (2) and

and the alkali metal salt is a triflate or a nonafluorobutanoate.

4 . A gas diffusion electrolytic flow cell comprising an anode electrode that produces oxygen by oxidizing water or hydroxide ions, a cathode electrode that produces a carbon dioxide reduction product by reducing carbon dioxide gas, and an ion-conductive polymer membrane that is sandwiched between the anode electrode and the cathode electrode, wherein

the cathode electrode comprises a catalyst layer and a gas diffusion layer in that order from a side of the ion-conductive polymer membrane, and

the catalyst layer has a metal complex catalyst, a carbon material and a solid alkali metal salt,

wherein the alkali metal salt in the catalyst layer exists in a solid state even during the reduction of carbon dioxide.

5 . The gas diffusion electrolytic flow cell according to claim 4 , wherein the alkali metal salt comprises a potassium salt.

6 . The gas diffusion electrolytic flow cell according to claim 4 , wherein the metal complex catalyst is selected from the group consisting of the following formulae (1), (2) and (3):

and the alkali metal salt is a triflate or a nonafluorobutanoate.