Patent ID: 8444875

Claim:
A burned composite metal oxide which is porous and particulate and which is obtained by subjecting a slurry comprising at least one metal oxide (a), at least one metal compound (b) and a solvent to spray granulation to obtain granules, and burning the granules, wherein the metal oxide (a) is selected from the group consisting of a transition metal oxide and an oxide of a metal belonging to 3B, 4B and 5B of a periodic table, the metal compound (b) is selected from the group consisting of an alkali metal compound and an alkali earth metal compound, the metal oxide (a) and the metal compound (b) are sparingly soluble in the solvent; the burning is conducted after a heat-maintaining step of heating the granules obtained by the spray granulation; the metal compound (b) contains at least a nonmetallic element component, wherein the nonmetallic element component desorbs from the metal compound (b) during the heat-maintaining step, thereby forming pores in the metal compound (b); and the burned composite metal oxide satisfies (I)-(IV): (I) an average aggregated particle diameter is 0.7 to 15 μm; (II) has a peak pore diameter at least in each of a range of 0.05 to 0.5 μm and a range of 0.5 μm to 10 μm, in a pore size distribution measured by a mercury porosimeter; (III) the BET specific surface area is 3.7 to 10 m 2 /g; and (IV) the total pore volume measured by the mercury porosimeter is 0.6 to 2 ml/g.