In a process for manufacturing a catalytic converter component, a ceramic unit is used that has been prepared by extruding green ceramic product through a die to form an extrusion having a honeycomb substrate structure in which tubular passages extend along the extrusion, the passages bounded by walls dividing adjacent passages from one another. The unit is obtained by cutting off a length of the extrusion and curing and firing it. The process further comprises flowing insulation material from one end of the unit into selected ones of the elongate passages, vaporizing a moisture content of the insulation material to form pores and curing the insulation material by using microwave irradiation to solidify the pores. The passages are selected so that the cured insulation material forms an internal thermal insulating barrier between a core zone of the unit and a radially outer zone of the unit.

A porous material includes an aggregate in which oxide films are formed on surfaces of particle bodies, and a binding material that contains cordierite and binds the aggregate together in a state where pores are formed. The binding material or the oxide films contain a rare-earth component that excludes Ce.

A silicon carbide porous body contains β-SiC particles, Si particles, and metal silicide particles. The maximum particle diameter of the β-SIC particles is not smaller than 15 μm. The content of the Si particles is not lower than 10 mass %. The maximum particle diameter of the Si particles is not larger than 40 μm. Further, an oxide coating film having a thickness not smaller than 0.01 μm and not larger than 5 μm is provided on surfaces of the Si particles.

A composite sintered body contains a silicon phase which is a main phase, a cordierite phase, and an amorphous phase containing Si. Further, the volume resistivity thereof at a room temperature is not lower than 0.1Ω.Math.cm and not higher than 2.5Ω.Math.cm.

A method for producing a honeycomb-shaped ceramic structure by extrusion-molding a moldable material including a cordierite-forming material and a pore-forming material, wherein the cordierite-forming material contains 15-25% by mass of silica having an average particle size of 20-30 μm, with 5% or less by mass of particles having particle sizes of 10 μm or less and 5% or less by mass of particles having particle sizes of 100 μm or more, a particle size distribution deviation SD of 0.5 or less, and sphericity of 0.5 or more, and wherein the pore-forming material is present in an amount of 5-40% by mass based on the cordierite-forming material and has an average particle size of 15-50 μm, with 10% or less by mass of particles having particle sizes of 5 μm or less and 5% or less by mass of particles having particle sizes of 80 μm or more.

The present invention relates to a metal oxide coated composite comprising a core consisting of a mixture of a La stabilised AI.sub.2O.sub.3 phase and an Ce/Zr/RE.sub.2O.sub.3 mixed oxide phase, the core having a specific crystallinity, specific pore volume and a specific pore size distribution, and a method for the production of the metal oxide coated composite.

Methods for producing porous carbon product utilize template material in the form of template particles containing macropores and a polymerizable carbon precursor substance. The macropores of the template are infiltrated with the precursor substance in dissolved or melted form. After carbonization of the infiltrated precursor substance, the template is removed to form the porous carbon product. In order to obtain a carbon structure with hierarchical porosity having a high fraction of mesopores having pore sizes in the range of 2 to 50 nm, after the infiltration and before carbonization, the precursor substance within the macropores of the template is subjected to a treatment at a foaming temperature at which the precursor substance foams under polycondensation and fills the macropores as substantially mesoporous foam, in which at least 70% of the pores have pore sizes in the range of 10 to 150 nm.

[Object] There is provided a porous sintered body has a uniform porosity, a high level of freedom in body formation which allows formation into varieties shapes and various levels of porosity, and a very large surface area. [Solution] The porous sintered body includes: hollow cores which follow a vanished shape of an interlaced or otherwise structured fibriform vanisher material; sintered walls 226 which extend longitudinally of the cores and obtained by sintering a first sintering powder held around the cores; and voids formed between the sintered walls. The cores and the voids communicate with each other via absent regions formed in the sintered walls. The sintered walls have surfaces formed with a sintered microparticulate layer 232 made from a material containing a second sintering powder which has a smaller diameter than the first sintering powder, and has predetermined pores 231.

A honeycomb structure includes a honeycomb structure body having a partition wall which is constituted of a porous body. The porous body includes a refractory aggregate and a bonding material. The porous body constituting includes the bonding material at a mass proportion of 20 to 35 mass %. In an observation of a cross section of the partition wall with an electron microscope, when observing any given ten visual fields meeting a following condition (1), the number of refractory aggregates meeting a following condition (2) is five pieces or more in all of the ten visual fields. Condition (1): a proportion of an area occupied by the bonding material is 30% or more. Condition (2): the refractory aggregate has a particle diameter of 5 μm or more, and 60% or more of an outer circumference of the refractory aggregate is surrounded by the bonding material.

The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows:

1.5≧T≧16×(100−P).sup.−1.4; and  Equation (1):

20≦P≦75.  Equation (2):