Metal oxide and method for producing the same, and catalyst

A method for producing a metal oxide, comprising:

• a first step of adding an alkaline material to an aqueous solution in which a compound of a metal element for forming an oxide is dissolved, thereby obtaining a precipitate of a precursor of said oxide;
• a second step of washing said precipitate;
• a third step of stirring said washed precipitate within a water together with a surfactant;
• and
• a fourth step of calcining a precipitate obtained after said third step, said first, second, third and fourth steps being carried out in order.

A method for producing a metal oxide comprising:

• a mixing step of forming a solution which comprises a cerium compound and zirconium compound, each compound decomposing by heating, and further comprises an organic substance such that said cerium compound and said zirconium compound are dissolved in said solution at least upon heating, and preparing a mixture in which at least one part of said organic substance is liquid after at least one part of said cerium compound and said zirconium compound decompose;
• a decomposing step of adding a surfactant to said mixture and heating an obtained mixture after stirring, whereby said obtained mixture decomposes and a homogeneous precursor is formed;
• and
• a calcining step of calcining said precursor such that said organic substance is burnt off, thereby forming a ceria-zirconia solid solution.