A honeycomb structure includes: a honeycomb structure portion comprising: an outer peripheral wall; a partition wall; and at least one slit cut radially inward from the outer peripheral wall. The outer peripheral wall and the partition contain SiC and Si. The at least one slit is filled with a filling material. At least one of two regions sandwiched between the pair of electrode layers on the outer surface of the outer peripheral wall has an information recognition portion for displaying information, and the information recognition portion has an area of a color tone range of 0.36≤x≤0.38, 0.38≤y≤0.41, 14≤Y≤100 of 250 mm.sup.2 or more in a CIExyY color space as defined in JIS Z 8781-3.

A CON zeolite satisfying the following (1) to (2): (1) The framework is CON as per the code specified by the International Zeolite Association (IZA); and (2) It contains silicon and aluminum, and the molar ratio of aluminum to silicon is 0.04 or more.

Provided is an exhaust gas purifying filter used with a HC purifying catalyst supported thereon. Numerous pores are formed in partitions of the exhaust gas purifying filter. In a cross-section of the partition, pores are open at a passage surface, having an open end of which the opening diameter is 50 μm or larger. In the cross-section of the partitions, the partitions include a narrow part where a pore diameter is 5 μm or more and the pore diameter becomes a minimum in a region. In the cross-section of the partitions, the region is positioned between a pair of virtual lines L.sub.1 and L.sub.2 extending from opposing sides of the opening end to a passage surface positioned opposite to the opening end along the wall thickness direction X, Z. The pore diameter at the narrow part is 6% or more and less than or equal to 20% of the opening diameter.

A gas purification device includes: a converter packed with a catalyst for hydrolyzing both carbonyl sulfide and hydrogen cyanide; an upstream heat exchanger for heat exchange between a gas to be introduced into the converter and a cooling fluid for cooling the gas; a reaction-temperature estimation member for estimating a reaction temperature inside the converter; and a flow-rate adjustment member for adjusting a flow rate of the cooling fluid flowing into the upstream heat exchanger based on an estimated value of the reaction-temperature estimation member to control the reaction temperature.

An aqueous suspension comprising water, a zeolitic material and one or more of copper and iron, and a chelate complex comprising a zirconium ion and a bidentate organic ligand bonded to said zirconium ion via zirconium oxygen bonds from two oxygen atoms comprised in said ligand, said chelate complex being dissolved in the water.

An exhaust gas purifying catalyst having first carrier particles, second carrier particles, and precious metal catalyst particles supported on the first and second carrier particles, wherein: the first carrier particles contain ceria, zirconia, and a rare-earth oxide other than ceria; the second carrier particles contain a rare-earth oxide other than ceria, and may contain ceria and zirconia; the contained proportion of ceria and zirconia in the first carrier particles is higher than the contained proportion of ceria and zirconia in the second carrier particles; the contained proportion of the rare-earth oxide in the second carrier particles is higher than the contained proportion of the rare-earth oxide in the first carrier particles; and the contained proportion of ceria in the first carrier particles is 45 wt % or less, while the precious metal catalyst particles include rhodium particles.

The invention relates to a particulate filter for removing particles, carbon monoxide, hydrocarbons and nitrogen oxides out of the exhaust gas of combustion engines operated with stoichiometric air/fuel mixture, comprising a wall flow filter with length L and a coating Z, wherein the wall flow filter includes channels E and A which extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls, which form surfaces OE or OA, and wherein the channels E are closed at the second end and the channels A are closed at the first end, characterised in that coating Z is located in the porous walls and extends from the first end of the wall flow filter over the entire length L, and includes active aluminum oxide, two different cerium/zirconium/rare earth metal mixed oxides and at least one platinum group metal.

The present invention relates to a metallic nanoparticle catalyst, and more particularly, to a porous catalyst in which metallic nanoparticles are embedded in a porous oxide support, and a method for preparing the porous catalyst. To this end, a porous catalyst composition having metallic nanoparticles of the present invention includes an oxide matrix structure having mesopores and micropores; and metal or metal oxide nanoparticles embedded in the oxide matrix structure having the mesopores and micropores. Thus, metallic nanoparticle catalysts having high activity even at low temperature are realized.

An exhaust gas purification filter includes a honeycomb structure part and sealing parts. The honeycomb structure part has a porous partition wall and a plurality of cells defined by the partition wall to form exhaust gas flow paths. The sealing parts seal alternately a gas inflow-side end face or a gas outflow-side end face of the cells. The exhaust gas purification filter includes fine pores with diameters of 10 μm or less measured by the mercury intrusion method that account for 5% or more of all pores by volume in the honeycomb structure part. The partition wall has a plurality of communication pores communicating between the cells adjacent to the partition wall and has constricted communication pore of which a largest diameter Φ.sub.1 and a smallest diameter Φ.sub.2 satisfy relationships Φ.sub.1≥50, 100×Φ.sub.2/Φ.sub.1≤20.

The present disclosure provides perovskite catalytic materials and catalysts comprising platinum-group metals and perovskites. These catalysts may be used as oxygen storage materials with automotive applications, such as three-way catalysts. They are also useful for water or CO.sub.2 reduction, or thermochemical energy storage.