Catalyst and process for producing same

A method for producing a catalyst comprising a catalytic metal comprising at least Ni, supported on a composite oxide, wherein said composite oxide comprises R (R stands for Ce or a mixture of Ce and Pr), Zr, and oxygen, at a composition of not less than 10 mol % and not more than 90 mol % of R, not less than 10 mol % and not more than 90 mol % of Zr, and not less than 0 mol % and not more than 20 mol % of M (M stands for elements other than oxygen, R, and Zr), with respect to a total of said elements other than oxygen being 100 mol %, wherein said composite oxide has a specific surface area of 11 to 90 m2/g, and a largest peak in the wavelength range of 200 to 800 cm−1 of Raman spectrum with a full width at half maximum of 20 to 72 cm−1, said method comprising:

• (a) preparing a mixed solution of a cerium solution not less than 80 mol % of which cerium ions are tetravalent, and zirconium hydroxide,
• (b) neutralizing said mixed solution to obtain a precursor of a composite oxide,
• (c) adding a surfactant to said precursor and mixing,
• (d) calcining said precursor mixed with the surfactant to obtain a composite oxide, and
• (e) making said composite oxide support a catalytic metal comprising at least Ni.