Core-shell support, method for producing the same, catalyst for purification of exhaust gas using the core-shell support, method for producing the same, and method for purification of exhaust gas using the catalyst for purification of exhaust gas

A core-shell support, comprising:

• a core which comprises at least one oxygen storage/release material selected from alumina-doped ceria-zirconia based solid solutions;
• and
• a shell which comprises a rare earth-zirconia based composite oxide represented by a composition formula:
• (Re1-xCex)2Zr2O7+x (where Re represents a rare earth element being at least one element selected from the group consisting of La, Nd, Pr, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, and x represents a number of 0.0 to 0.8) and with which an outside of the core is coated,
• the rare earth-zirconia based composite oxide comprising crystal particles having a pyrochlore structure, and
• the rare earth-zirconia based composite oxide having an average crystallite diameter of 3 to 9 nm, wherein
• an amount of the rare earth-zirconia based composite oxide constituting the shell is 4 to 24 parts by mass relative to 100 parts by mass of the oxygen storage/release material constituting the core.