摘要:
A hexagonal-cell honeycomb carrier body, made of cordierite ceramic, for use in a carrier of a catalyst of purifying exhaust gas is disclosed as including a large number of hexagonal cells surrounded with cell walls formed in a hexagonal lattice pattern and a cylindrical skin layer covering outer circumferential sidewalls of the hexagonal cells. The hexagonal-cell honeycomb carrier body has GSA (Geometric Surface Area) of 3.5 mmW or more. A hexagonal-cell honeycomb catalyst body comprises the hexagonal-cell honeycomb carrier body and a catalyst layer which covers a surface of the hexagonal-cell honeycomb carrier body.
摘要:
An exhaust emission control catalyst disclosed herein is equipped with a rhodium catalytic layer and a platinum catalytic layer, and is characterized in that a relationship between a mole average (X) of a Pauling's electronegativity that is calculated as to elements included in the rhodium catalytic layer except platinum group elements and oxygen and a mole average (Y) of a Pauling's electronegativity that is calculated as to elements included in the platinum catalytic layer except platinum group elements and oxygen is 1.30≦X≦1.45 and 1.47≦Y≦2.0. According to this exhaust emission control catalyst, an interlayer transfer of platinum and/or rhodium and the alloying of platinum and/or rhodium are suppressed during use of the catalyst, and high exhaust gas purification performance can be exerted.
摘要:
A honeycomb-shaped substrate for catalyst is made from ceramic, has a straight-flow structure, and includes cellular walls exhibiting pore volumes, which differ partially, and a large number of cellular passages demarcated by the cellular walls. A catalyst for purifying exhaust gases is produced by providing the cellular walls of the honeycomb-shaped substrate with a catalytic coating layer.
摘要:
A honeycomb-shaped substrate for catalyst is made from ceramic, has a straight-flow structure, and includes cellular walls exhibiting pore volumes, which differ partially, and a large number of cellular passages demarcated by the cellular walls. A catalyst for purifying exhaust gases is produced by providing the cellular walls of the honeycomb-shaped substrate with a catalytic coating layer.
摘要:
An exhaust emission control catalyst disclosed herein is equipped with a rhodium catalytic layer and a platinum catalytic layer, and is characterized in that a relationship between a mole average (X) of a Pauling's electronegativity that is calculated as to elements included in the rhodium catalytic layer except platinum group elements and oxygen and a mole average (Y) of a Pauling's electronegativity that is calculated as to elements included in the platinum catalytic layer except platinum group elements and oxygen is 1.30≦X≦1.45 and 1.47≦Y≦2.0. According to this exhaust emission control catalyst, an interlayer transfer of platinum and/or rhodium and the alloying of platinum and/or rhodium are suppressed during use of the catalyst, and high exhaust gas purification performance can be exerted.
摘要:
A formed article is made of cordierite. The cordierite has a plurality of domains and a plurality of crystal grains placed in each domain to form a domain structure. The crystal grains in each domain are substantially aligned in the same direction, and an average size of the domains ranges from 40 μm to 150 μm. The article of cordierite is formed in a honeycomb structure having a plurality of cell walls arranged in a honeycomb form, and a plurality of cells divided by the cell walls are formed. The article of cordierite has a porosity ranging from 36% to 38%, a coefficient of linear thermal expansion equal to or lower than 0.2×106/K and a mechanical strength equal to or higher than 60×106 Pa.
摘要:
It is to provide a method for producing a monolithic catalyst for exhaust gas purification, which can effectively perform exhaust gas purification in accordance with the shape of an exhaust manifold of a catalytic converter, and to provide a monolithic catalyst. The monolithic catalyst has a catalyst coat layer in the axial center region of a substrate, which includes the axial center of an exhaust pipe and has a lower end corresponding to a projected plane of the cross-section of the exhaust pipe, in an amount larger than in a peripheral region other than the axial center region of the substrate. The process of forming the catalyst coat layer which has this distribution of coating amount comprises maintaining a slurry for forming the catalyst coat layer in an approximately truncated conical shape, bringing one end of the monolithic catalyst substrate into close contact with a horizontal side of the slurry, and sucking once the slurry from the other end of the substrate.
摘要:
An automobile exhaust gas catalytic converter includes a first catalyst layer; a second catalyst layer located on a downstream side as compared to the first catalyst layer; and a base material on which the first catalyst layer and the second catalyst layer are respectively located. In the exhaust gas catalytic converter, the proportion (LB/LS) of a coating length (LB) of the second catalyst layer from a downstream end of the base material with respect to a total length (LS) of the base material in the exhaust gas flow direction is approximately 50 to 90%, the proportion of an amount of Rh contained in the second catalyst layer with respect to a total amount of Rh contained in the first catalyst layer and the second catalyst layer is approximately 50 to 90% by mass, and the rest of Rh is contained together with Pd or Pt in the first catalyst layer.
摘要:
An automobile exhaust gas catalytic converter includes a first catalyst layer; a second catalyst layer located on a downstream side as compared to the first catalyst layer; and a base material on which the first catalyst layer and the second catalyst layer are respectively located. In the exhaust gas catalytic converter, the proportion (LB/LS) of a coating length (LB) of the second catalyst layer from a downstream end of the base material with respect to a total length (LS) of the base material in the exhaust gas flow direction is approximately 50 to 90%, the proportion of an amount of Rh contained in the second catalyst layer with respect to a total amount of Rh contained in the first catalyst layer and the second catalyst layer is approximately 50 to 90% by mass, and the rest of Rh is contained together with Pd or Pt in the first catalyst layer.
摘要:
A hexagonal-cell honeycomb structure having a plurality of cell walls having a hexagonal shape in cross-section and forming a plurality of hexagonal cell passages, and a tubular skin layer surrounding the cell walls, The thickness of the basic cell walls is 140 μm or less and an inscribed circle diameter Da inscribed at an intersectional portion of the basic cell walls 2 and an cell pitch P having the relationship Da/P≧0.13.