Abstract: This exhaust gas cleaning catalytic device includes a base material and a first catalyst coat layer on the base material. The first catalyst coat layer has a pre-stage section on an exhaust gas flow upstream side, and a post-stage section on an exhaust gas flow downstream side. The first catalyst coat layer pre-stage section and post-stage section each contain inorganic oxide particles and rhodium supported by the inorganic oxide particles, while at least some of the inorganic oxide particles contain ceria. The ceria amount per unit length of the first catalyst coat layer post-stage section is larger than the ceria amount per unit length of the first catalyst coat layer pre-stage section. The first catalyst coat layer pre-stage section is disposed in such a manner that the end portion on the exhaust gas flow upstream side thereof is in direct contact with the exhaust gas flow.

Abstract: This exhaust gas cleaning catalytic device includes a base material and a first catalyst coat layer on the base material. The first catalyst coat layer has a pre-stage section on an exhaust gas flow upstream side, and a post-stage section on an exhaust gas flow downstream side. The first catalyst coat layer pre-stage section and post-stage section each contain inorganic oxide particles and rhodium supported by the inorganic oxide particles, while at least some of the inorganic oxide particles contain ceria. The ceria amount per unit length of the first catalyst coat layer post-stage section is larger than the ceria amount per unit length of the first catalyst coat layer pre-stage section. The first catalyst coat layer pre-stage section is disposed in such a manner that the end portion on the exhaust gas flow upstream side thereof is in direct contact with the exhaust gas flow.

Abstract: A Pd-supporting Zr-based composite oxide wherein by having a Zr-containing composite oxide support and Pd supported thereon and by showing, upon XAFS (X-ray absorption fine structure) analysis, a maximum peak in a Pd bond distance range of 2.500-3.500 ?, the maximum peak being located in a position of 3.050-3.110 ?.

Abstract: An exhaust gas purification catalyst of the present invention is provided with a base 10 and a catalyst coat layer 30. The catalyst coat layer is provided with Rh and Pd as noble metal catalysts. Herein Rh is disposed in a first-stage upper layer A and a second-stage upper layer C, and Pd is disposed in the first-stage upper layer A and a first-stage lower layer B, and in a second-stage lower layer D. A mass ratio (APd/ARh) of Pd to Rh, disposed in first-stage upper layer A is 0.5?(APd/ARh)?3.

Abstract: An exhaust gas purification catalyst of the present invention is provided with a base 10 and a catalyst coat layer 30. The catalyst coat layer is provided with Rh and Pd as noble metal catalysts. Herein Rh is disposed in a first-stage upper layer A and a second-stage upper layer C, and Pd is disposed in the first-stage upper layer A and a first-stage lower layer B, and in a second-stage lower layer D. A mass ratio (APd/ARh) of Pd to Rh, disposed in first-stage upper layer A is 0.5?(APd/ARh)?3.

Abstract: An exhaust gas purifying catalyst according to the present invention is provided with a base material 10 and a catalyst-coated layer 30. The catalyst-coated layer 30 is provided with a lower layer 34 and an upper layer 32. The upper layer 32 contains Rh and/or Pt as a noble metal catalyst. The lower layer 34 contains Pd as a noble metal catalyst. The lower layer 34 is provided with a front-stage lower layer 34a positioned on an upstream side and a rear-stage lower layer 34b positioned on a downstream side. The front-stage lower layer 34a is a Ce-free layer that does not contain a Ce-containing oxide. The rear-stage lower layer 34b is a Ce-containing layer that contains a Ce-containing oxide with a pyrochlore structure.

Abstract: A Pd-supporting Zr-based composite oxide wherein by having a Zr-containing composite oxide support and Pd supported thereon and by showing, upon XAFS (X-ray absorption fine structure) analysis, a maximum peak in a Pd bond distance range of 2.500-3.500 ?, the maximum peak being located in a position of 3.050-3.110 ?.

Abstract: The exhaust gas purification catalyst according to the present invention includes a substrate 10 and a catalyst coat layer 30. The catalyst coat layer 30 is formed into a multilayer structure having a lower layer 32, a middle layer 34 and an upper layer 36. The upper layer 36 contains Rh and a Ce-containing oxide. The lower layer 32 contains Pd and a Ce-containing oxide. The middle layer 34 is a Ce-free layer that contains Pd but does not contain a Ce-containing oxide. A ratio (B/A) of the content B of Ce in the lower layer 32 to the content A of Ce in the upper layer 36 satisfies 2?(B/A).

Abstract: An exhaust gas purifying catalyst according to the present invention is provided with a base material 10 and a catalyst-coated layer 30. The catalyst-coated layer 30 is provided with a lower layer 34 and an upper layer 32. The upper layer 32 contains Rh and/or Pt as a noble metal catalyst. The lower layer 34 contains Pd as a noble metal catalyst. The lower layer 34 is provided with a front-stage lower layer 34a positioned on an upstream side and a rear-stage lower layer 34b positioned on a downstream side. The front-stage lower layer 34a is a Ce-free layer that does not contain a Ce-containing oxide. The rear-stage lower layer 34b is a Ce-containing layer that contains a Ce-containing oxide with a pyrochlore structure.

Abstract: A bulk-density measuring device includes a first vessel in which contracted pre-expanded particles are swollen and recovered from contraction in a pressure-reduced state where a vessel internal pressure is lower than atmospheric pressure; a second vessel filled with the pre-expanded particles after being swollen in the first vessel in the pressure-reduced state where a vessel internal pressure is lower than the atmospheric pressure, and into which the pre-expanded particles of a constant volume are collected fractionally; a pressure-reducing unit that adjusts the vessel internal pressures of the first vessel and the second vessel to be lower than the atmospheric pressure; and a scale that measures a weight of the pre-expanded particles filled in the second vessel.

Abstract: A bulk-density measuring device includes a first vessel in which contracted pre-expanded particles are swollen and recovered from contraction in a pressure-reduced state where a vessel internal pressure is lower than atmospheric pressure; a second vessel filled with the pre-expanded particles after being swollen in the first vessel in the pressure-reduced state where a vessel internal pressure is lower than the atmospheric pressure, and into which the pre-expanded particles of a constant volume are collected fractionally; a pressure-reducing unit that adjusts the vessel internal pressures of the first vessel and the second vessel to be lower than the atmospheric pressure; and a scale that measures a weight of the pre-expanded particles filled in the second vessel.