Disclosed herein are a catalyst composition, catalyst devices, and methods for removing formaldehyde, volatile organic compounds, and other pollutants from an air flow stream. The catalyst composition including manganese oxide, optionally one or more of alkali metals, alkaline earth metals, zinc, iron, binder, an inorganic oxide, or carbon.

A hydrocarbon removal system according an embodiment of the present invention includes: a first area including a first hydrocarbon adsorption catalyst having a first pore size; and a second area including a second hydrocarbon adsorption catalyst having a second pore size, wherein the first pore size may be smaller than the second pore size, the first hydrocarbon adsorption catalyst may include CHA zeolite, and the second hydrocarbon adsorption catalyst may include ZSM-5 zeolite.

The present invention relates to an ammonia oxidation catalyst for the treatment of an exhaust gas stream, the catalyst comprising a coating disposed on a substrate, wherein the coating comprises a selective catalytic reduction component being a zeolitic material comprising one or more of copper and iron; and an oxidation catalytic component comprising platinum supported on a porous non-zeolitic oxidic support, wherein the oxidation catalytic component further comprises a first oxidic material supported on the porous non-zeolitic oxidic support supporting platinum, wherein the first oxidic material comprises titania.

A porous material includes an aggregate, and a binding material that binds the aggregate together in a state where pores are formed. The porous material contains 0.1 to 10.0 mass % of an MgO component, 0.5 to 25.0 mass % of an Al.sub.2O.sub.3 component, and 5.0 to 45.0 mass % of an SiO.sub.2 component with respect to the mass of the whole porous material, and further contains 0.01 to 5.5 mass % of an Sr component in terms of SrO.

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 particulate material and a process for the production thereof are provided, which particulate material comprises zeolitic particles having a crystalline structure, which contain as the main component a zeolite material having a zeolitic framework structure formed from Si, O and optionally Al, and/or a zeolite-like material having a zeolitic framework structure which is formed not only from Si, O and optionally Al, wherein the zeolitic particles are in the form of essentially spherical particles with nanometer dimensions.

A composite material is used for desulfurization. The composite material contains activated carbon, alkali metal oxides, silicon oxides, iron oxides, and rare earth element oxides. The weight ratio among the activated carbon, iron oxides and rare earth element oxides is 100:(0.5-5):(1-10). The composite material, used as a sulfur adsorbent, has a higher sulfur breakthrough capacity and desulfurization rate.

A metal-supported catalyst, battery electrode, and battery, each having excellent catalytic activity and durability. The metal-supported catalyst includes: a carbon carrier; and catalyst metal particles supported thereon, wherein, in a photoelectron spectrum obtained by X-ray photoelectron spectroscopy, the catalyst exhibits, as a peak derived from a is orbital of a nitrogen atom, a peak to be separated into peaks of first to sixth nitrogen atoms having peak tops in the following respective ranges: (1) 398.6±0.2 eV; (2) 399.5±0.3 eV; (3) 400.5±0.2 eV; (4) 401.3±0.3 eV; (5) 403.4±0.4 eV; and (6) 404.5±0.5 eV, wherein a ratio of a peak area of the second nitrogen atoms to a total peak area of the nitrogen atoms of the (1) to (6) is 0.03 or more, and wherein a ratio of a concentration of the second nitrogen atoms to a concentration of carbon atoms measured by the X-ray photoelectron spectroscopy is 0.0005 or more.

A metal-supported catalyst, a battery electrode, and a battery, each having both excellent catalytic activity and durability. The metal-supported catalyst includes: a carbon carrier; and catalyst metal particles each containing a noble metal supported on the carbon carrier, wherein a volume of first pores each having a diameter of 0.5 nm or more and 2.0 nm or less per unit weight of the carbon carrier is 0.20 (cm.sup.3/g-carrier) or more, wherein a volume of second pores each having a diameter of more than 2.0 nm and 4.0 nm or less per unit weight of the carbon carrier is 0.20 (cm.sup.3/g-carrier) or more, and wherein a ratio of a content (wt %) of the noble metal measured by X-ray photoelectron spectroscopy, to a content (wt %) of the noble metal measured by inductively coupled plasma mass spectrometry, is 0.35 or more and 0.75 or less.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein the partition wall is composed of a material containing cordierite as a main component thereof, porosity of the partition wall measured by a mercury press-in method is 60 to 68%, an average pore diameter of the partition wall measured by a mercury press-in method is 19 to 26 μm, and in a pore diameter distribution indicating a cumulative pore volume of the partition wall measured by a mercury press-in method, with a pore diameter (μm) on an abscissa axis and a log differential pore volume (cm.sup.3/g) on an ordinate axis, a first peak including a maximum value of the log differential pore volume has a pore diameter value of 18 μm or less, the pore diameter value corresponding to a ⅓ value width of the maximum value.