Abstract: The problem to be solved by the present invention is to provide an oxygen storage and release material comprising a ceria-zirconia-based complex oxide improved in ability to remove HC and NOx and a three-way catalyst able to reduce an amount of NOx emission. Further, to solve this problem, an oxygen storage and release material comprising a ceria-zirconia-based complex oxide containing Gd2O3 in 0.1 mol % or more and less than 20 mol % and having an ion conductivity of 2×10?5 S/cm or more at 400° C. is provided. Further, in addition to the above, an oxygen storage and release material having a molar ratio of cerium and zirconium of 0.2 or more and 0.6 or less by cerium/(cerium+zirconium) and an speed of oxygen storage and release “?t50” of 20.0 seconds or more or amount of oxygen storage and release of 300 ?mol-O2/g or more etc. was obtained.

Abstract: The problem to be solved by the present invention is to provide an oxygen storage and release material comprising a ceria-zirconia-based complex oxide improved in ability to remove HC and NOx and a three-way catalyst able to reduce an amount of NOx emission. Further, to solve this problem, an oxygen storage and release material comprising a ceria-zirconia-based complex oxide containing Gd2O3 in 0.1 mol % or more and less than 20 mol % and having an ion conductivity of 2×10?5 S/cm or more at 400° C. is provided. Further, in addition to the above, an oxygen storage and release material having a molar ratio of cerium and zirconium of 0.2 or more and 0.6 or less by cerium/(cerium+zirconium) and an speed of oxygen storage and release “?t50” of 20.0 seconds or more or amount of oxygen storage and release of 300 ?mol-O2/g or more etc. was obtained.

Abstract: A ceria-zirconia-based composite oxide oxygen storage material with a fast oxygen storage rate having an OSC ability enabling fast response to changes in exhaust gas which does not greatly fluctuate in composition, but varies at a fast rate near the stoichiometric air-fuel ratio, an exhaust gas purification catalyst, and a honeycomb structure for exhaust gas purification are provided. A ceria-zirconia-based composite oxide oxygen storage material, which oxygen storage material has a molar ratio of cerium and zirconium, by cerium/(cerium+zirconium), of 0.33 to 0.90, has an ion conductivity measured by an AC impedance method of 1×10?5S/cm or more at 400° C., and contains metal ions M of one or more types of rare earth elements selected from Sm3+, Eu3+, Pr3+, Gd3+, and Dy3+ with a coordination number of over 7.0 in an amount of 0.5 mol % to 15 mol % with respect to the total amount of cations.

Abstract: A ceria-zirconia-based composite oxide oxygen storage material with a fast oxygen storage rate having an OSC ability enabling fast response to changes in exhaust gas which does not greatly fluctuate in composition, but varies at a fast rate near the stoichiometric air-fuel ratio, an exhaust gas purification catalyst, and a honeycomb structure for exhaust gas purification are provided. A ceria-zirconia-based composite oxide oxygen storage material, which oxygen storage material has a molar ratio of cerium and zirconium, by cerium/(cerium+zirconium), of 0.33 to 0.90, has an ion conductivity measured by an AC impedance method of 1×10?5 S/cm or more at 400° C., and contains metal ions M of one or more types of rare earth elements selected from Sm3+, Eu3+, Pr3+, Gd3+, and Dy+3 with a coordination number of over 7.0 in an amount of 0.5 mol % to 15 mol % with respect to the total amount of cations.

Abstract: A ceria-zirconia-based composite oxide which has a crystal phase of the composite oxide of a single solid-solution phase even after exposure to a high temperature over a long time and has a small change in mode pore diameter and in pore volume before and after a high temperature durability test is provided. This is realized by a ceria-zirconia-based composite oxide having a chemical composition, by mass ratio, of zirconia: 30% to 80%, a total of oxides of one or more elements selected from yttrium and rare earth elements having atomic number 57 to 71 (except cerium and promethium): 0% to 20%, and a balance of ceria and unavoidable impurities, in which ceria-zirconia-based composite oxide, the composite oxide is deemed to be a single solid-solution phase in an X-ray diffraction pattern after a durability test which heats the oxide in the atmosphere at a temperature condition of 1100° C.

Abstract: A ceria-zirconia-based composite oxide which has a crystal phase of the composite oxide of a single solid-solution phase even after exposure to a high temperature over a long time and has a small change in mode pore diameter and in pore volume before and after a high temperature durability test is provided. This is realized by a ceria-zirconia-based composite oxide having a chemical composition, by mass ratio, of zirconia: 30% to 80%, a total of oxides of one or more elements selected from yttrium and rare earth elements having atomic number 57 to 71 (except cerium and promethium): 0% to 20%, and a balance of ceria and unavoidable impurities, in which ceria-zirconia-based composite oxide, the composite oxide is deemed to be a single solid-solution phase in an X-ray diffraction pattern after a durability test which heats the oxide in the atmosphere at a temperature condition of 1100° C.