Electrochemical reaction unit cell, and electrochemical reaction cell stack

1. An electrochemical reaction unit cell comprising:

an electrolyte layer containing Zr;

an anode disposed on one side of the electrolyte layer in a first direction;

a cathode containing Sr and disposed on another side of the electrolyte layer in the first direction; and

a reaction preventing layer containing Gd and disposed between the electrolyte layer and the cathode,

wherein the reaction preventing layer contains Zr in an amount of 0.015 wt % to 1 wt %,

a Sr/Gd intensity ratio is less than 50% at a first reference point around a boundary between the reaction preventing layer and the electrode layer, and

the first reference point is located at a position around the boundary where a curve representing intensity of ZrO intersects with a curve representing intensity of Gd on a graph of intensity data with respect to a plurality of positions aligned in the first direction around the boundary.

2. The electrochemical reaction unit cell as claimed in claim 1 , wherein the reaction preventing layer contains Zr in an amount of 0.015 wt % to 0.18 wt %.

3. The electrochemical reaction unit cell as claimed in claim 1 , wherein the reaction preventing layer contains Zr in an amount of 0.05 wt % to 1 wt %.

4. The electrochemical reaction unit cell as claimed in claim 1 , wherein the electrolyte layer contains a solid oxide.

5. The electrochemical reaction unit cell as claimed in claim 1 , wherein the electrochemical reaction unit cell is a fuel cell unit cell.

6. An electrochemical reaction cell stack comprising a plurality of electrochemical reaction unit cells including at least one electrochemical reaction unit cell as claimed in claim 1 disposed in the first direction.