A photocatalyst has a perovskite type crystal, the photocatalyst has, present on a surface, a stepped structure including a terrace and a step, and an occupancy ratio of a projected area of the stepped structure to a total projected area in an observation image of the surface is 20% or more. It is preferable that the terrace is formed of a {100} facet, and the step is formed of the {100} facet or a {110} facet.

Catalysts and catalytic methods are provided. The catalysts and methods are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane.

A highly active catalyst particle includes a photocatalyst 2 and a cocatalyst 3 supported on the photocatalyst 2, in which the cocatalyst 3 contains a first cocatalyst 31 and a second cocatalyst 32, the first cocatalyst 31 contains at least one of Group 3 to Group 7 elements, the second cocatalyst 32 contains at least one of Group 8 to Group 11 elements, and the photocatalyst 2 contains titanium at 16 at % or more, and decomposes water under light irradiation to generate hydrogen and oxygen.