PLATINUM-CONTAINING CATALYST, PROCESS FOR PRODUCING THE PLATINUM-CONTAINING CATALYST, ELECTRODE, AND ELECTROCHEMICAL DEVICE

There are provided a core-shell type platinum-containing catalyst being allowed to reduce the amount of used platinum and having high catalytic activity and stability and a method of producing the same, an electrode and an electrochemical device. The core-shell type platinum-containing catalyst includes a core particle (with an average particle diameter R) made of a non-platinum element and a platinum shell layer (with an average thickness t) satisfying 1.4 nm≤R≤3.5 nm and 0.25 nm≤t≤0.9 nm. The core particle includes an element satisfying E≥3.0 eV, where average binding energy relative to the Fermi level of 5d orbital electrons of platinum present on an outermost surface of the shell layer is E. In a fuel cell including a platinum-containing catalyst which contains a Ru particle as a core particle, the output density at a current density of 300 mA/cmis 70 mW/cmor over, and an output retention ratio is approximately 90% or over.