Electrochemical hydrogen pump

1. An electrochemical hydrogen pump comprising:

an electrolyte membrane;

a cathode catalyst layer provided on a first principal surface of the electrolyte membrane, the cathode catalyst layer including a cathode gas diffusion layer;

an anode catalyst layer provided on a second principal surface of the electrolyte membrane, the anode catalyst layer including an anode gas diffusion layer;

a pair of separators which include gas flow paths and which are provided so as to sandwich the cathode catalyst layer and the anode catalyst layer;

an anode chamber which is in communication with the gas flow path of one of the separators of the pair of separators;

a cathode chamber which is in communication with the gas flow path of the other separator of the pair of separators; and

a voltage application portion applying a voltage between the cathode catalyst layer and the anode catalyst layer,

wherein the first principal surface is disposed at an upper side in the gravity direction, and

the cathode catalyst layer has a hydrophilic property,

wherein the cathode catalyst layer comprises hydrophilic particles and a pore forming polymer on a surface of the cathode catalyst layer provided by treating the surface of the cathode catalyst layer with a paste containing the hydrophilic particles and the pore forming polymer and solidifying the paste,

wherein one of the separators of the pair of separators is located between the anode gas diffusion layer and the anode chamber and the other separator of the pair of separators is located between the cathode gas diffusion layer and the cathode chamber,

wherein the pore forming polymer is selected from the group consisting of a polysulfone (PSU), a poly(vinylidene fluoride) (PVDF), a polyacrylonitrile (PAN), a polyethylene oxide) (PEO), a polymethylmethacrylate, and a copolymer thereof,

wherein the paste further contains a compound selected from the group consisting of polypropylene glycol), glycerin, ethylene glycol, tripropylene glycol, dibutyl phthalate (DBP), diethyl phthalate (DEP), diundecyl phthalate (DUP), isononanoic acid, and neodecanoic acid.

2. The electrochemical hydrogen pump according to claim 1 , wherein the cathode catalyst layer has a contact angle of 90 or less.

3. The electrochemical hydrogen pump according to claim 1 , wherein a hydrophilic property of the cathode catalyst layer is greater than the hydrophilic property of the anode catalyst layer.

4. The electrochemical hydrogen pump according to claim 1 , wherein a hydrophilic property of the cathode catalyst layer is greater than the hydrophilic property of the cathode gas diffusion layer.