An object of the present invention is to provide an exhaust gas purification catalyst which can exhibit high durability and warm-up performance. The present invention relates to an exhaust gas purification catalyst comprising a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises catalyst particles, the catalyst coating layer having an upstream region extending by 40 to 60% of the entire length of the substrate from an upstream end of the catalyst in the direction of an exhaust gas flow and a downstream region corresponding to the remainder portion of the catalyst coating layer, the composition of the catalyst particle of the upstream region being different from that of the downstream region. The upstream region in the direction of an exhaust gas flow has a structure where a void is included in a large number, and furthermore high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain percentage or more of the whole volume of voids. Thus, the exhaust gas purification catalyst exhibits enhanced purification performance.

An object of the present invention is to provide an exhaust gas purification catalyst which can exhibit sufficient purification performance even under a high Ga condition. The present invention relates to an exhaust gas purification catalyst comprising a substrate and a catalyst coating layer formed on the substrate, wherein the catalyst coating layer comprises catalyst particles, the catalyst coating layer having an upstream region extending by 40 to 60% of the entire length of the substrate from an upstream end of the catalyst in the direction of an exhaust gas flow and a downstream region corresponding to the remainder portion of the catalyst coating layer, the composition of the catalyst particle of the upstream region being different from that of the downstream region. The downstream region in the direction of an exhaust gas flow has a structure where a void is included in a large number, and furthermore high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain percentage or more of the whole volume of voids. Thus, the exhaust gas purification catalyst exhibits enhanced purification performance.

Disclosed is a visible light-activated photocatalytic coating composition comprising a visible light active photocatalytic material and an aqueous solvent.

The present invention provides a photocatalytic composition comprising: a photocatalyst; and an adsorbent material.

A steam generator for a power plant sub-system, having at least one evaporator tube through which a flow medium can flow, as well as a number of heat exchanger surfaces formed by the surface of the evaporator tube, wherein at least parts of the/each heat exchanger surface are provided with a catalytically active coating for the exothermic decomposition of hydrocarbons. By means of the catalytic coating of the heat exchanger surfaces of the evaporator tubes, an increased heat requirement calculation can be carried out, without also having to accept the formation of unwanted harmful substances inside the steam generator.

The problem of the present invention is to provide an exhaust gas purification catalyst which can exhibit sufficient purification performance under a high Ga condition while having a resistance to stress such as high-temperature and poisonous substances. The present invention relates to an exhaust gas purification catalyst comprising two or more catalyst coating layers on a substrate, wherein a lower catalyst coating layer that is present lower with respect to an uppermost catalyst coating layer has a structure where a large number of voids are included and high-aspect-ratio pores having an aspect ratio of 5 or more account for a certain proportion or more of the whole volume of voids, thereby to improve gas diffusivity in the lower catalyst coating layer.

When the amount of coating is increased in a two-layer catalyst or the like containing two noble metals in respective different layers, gas diffusivity in the catalyst and use efficiency of a catalytic active site are reduced to thereby reduce purification performance. In view of this, an organic fiber having a predetermined shape is used as a pore-forming material in formation of an uppermost catalyst coating layer of a multi-layer catalyst, to thereby form an uppermost catalyst coating layer having a high-aspect-ratio pore excellent in connectivity and therefore excellent gas diffusivity.

A method is disclosed for removing ozone from a gas. According to this method, the gas is contacted with an adsorbent that includes a transition metal oxide or metal organic framework to form a treated gas. The treated gas is contacted with a noble metal catalyst to catalytically decompose ozone in the treated gas, thereby forming an ozone-depleted treated gas.

A core-shell support, comprising: a core which comprises at least one oxygen storage/release material selected from the group consisting of ceria-zirconia based solid solutions and alumina-doped ceria-zirconia based solid solutions; and a shell which comprises a rare earth-zirconia based composite oxide represented by a composition formula: (Re.sub.1-xCe.sub.x).sub.2Zr.sub.2O.sub.7+x (where Re represents a rare earth element, and x represents a number of 0.0 to 0.8) and with which an outside of the core is coated, the rare earth-zirconia based composite oxide comprising crystal particles having a pyrochlore structure, and the rare earth-zirconia based composite oxide having an average crystallite diameter of 3 to 9 nm.

An exhaust flue cap and filter device for a gas fired appliance in communication with an exhaust flue opening. The device includes an inner collar to engage the exhaust flue opening. A tubular cap with a closed lower end is in communication with the inner collar. A filter tray is suspended in the tubular cap wherein the filter tray has a smaller diameter than the tubular cap so that a bypass space is formed between the filter tray and the tubular cap to permit passage of exhaust gases. A removable filter insert is receivable in the filter tray. A removable top having a body with exhaust openings is attached to and closes the open upper end of the tubular cap.