Abstract: Provided are an electrode to enhance the power generation efficiency in a fuel cell, in particular a single-chamber solid electrolyte fuel cell, and such an electrode. The electrode of the present invention comprises ?Eh, represented by the following formula (1), being not less than ?10 mV and not more than 100 mV. ?Eh=E0?E3??(1) (where E0 denotes an electrode potential when a gas having a hydrogen concentration of 0% (an oxidizing gas only) makes contact with the electrode at room temperature, and E3 denotes an electrode potential when a mixed gas having a hydrogen concentration of 3 volume % (a hydrogen gas and the oxidizing gas) makes contact with the electrode at room temperature.

Abstract: It is an object of the present invention to provide an electrode catalyst composition capable of forming an electrode to enhance the power generation efficiency in a fuel cell, in particular a single-chamber solid electrolyte fuel cell. The electrode catalyst composition of the present invention comprises gold and platinum, wherein the number of gold atoms is exceeding 0 and not more than 3 when the number of platinum atoms is 100.