The present invention relates to new crystalline zeolite SSZ-52x prepared using a quaternary ammonium cation templating agent, for example, having the structure:

##STR00001##

wherein X.sup.− is an anion which is not detrimental to the formation of the SSZ-52x. SSZ-52x is useful as a catalyst and shows improved durability, particularly with regard to NO.sub.x conversion.

A composition is provided that has heat resistance sufficient for use as a hydrocarbon adsorbent and desorbs hydrocarbons slowly with respect to an increase in temperature. The composition includes an alkali metal and a zeolite having a YFI structure. A content of the alkali metal is 1 to 40 mass% based on a total mass of the composition, and a content of the zeolite having a YFI structure is 99 to 60 mass% based on the total mass of the composition.

A pillar-shaped honeycomb structure including an outer peripheral side wall, a plurality of first cells provided on an inner peripheral side of the outer peripheral side wall, the first cells extending from a first end surface to a second end surface, each opening on the first end surface and having a sealing portion with an average void ratio of 4% or less on the second end surface, and a plurality of second cells provided on the inner peripheral side of the outer peripheral side wall, the second cells extending from the first end surface to the second end surface, each having a sealing portion with an average void ratio of 4% or less on the first end surface and opening on the second end surface, the first cells and the second cells being alternately arranged adjacent to each other with a partition wall interposed therebetween.

The present invention concerns a material with a non-stoichiometric spinel-type crystalline structure based on cobalt oxide doped with alkaline elements, its production process for obtaining it by precipitation with controlled washing, and its particular use as a highly active catalyst in the N.sub.2O decomposition reaction. Therefore, we understand that the present invention is in the area of green industry aimed at reducing N.sub.2O emissions into the atmosphere.

A hydrocarbon adsorbent having a high hydrocarbon desorption start temperature and a method for adsorbing hydrocarbons that uses the hydrocarbon adsorbent are provided. The hydrocarbon adsorbent includes an alkali metal and a zeolite having a ring structure that includes at least 10 members is used. In the hydrocarbon adsorbent, a content of the alkali metal is 1 to 40 mass % based on a total mass of the hydrocarbon adsorbent, a content of the zeolite having a ring structure that includes at least 10 members is 99 to 60 mass % based on the total mass of the hydrocarbon adsorbent, and at least a portion of the alkali metal is in a state of being ion-exchangeable.

Process for the removal of NOx (NO, NO2) and nitrous oxide (N2O) contained in a process off-gas comprising the steps of (a) adding an amount of a NOx reducing agent into the process off-gas;(b) in a first stage passing the process off-gas admixed with the reducing agent through a catalyst active in selective catalytic reduction of NOx with the reducing agent and providing an effluent gas comprising the nitrous oxide and residual amounts of reducing agent; and(c) in a second stage passing the effluent gas through a catalyst comprising a cobalt compound and being active in decomposition of nitrous oxide and oxidation of the residual amounts of the reducing agent.

A process for altering the composition of a feed gas containing H.sub.2S equivalents is disclosed. The process comprises (a) contacting the feed gas with a solid adsorbent at a temperature of 250-500° C., to obtain a loaded adsorbent, (b) purging the loaded adsorbent with a purge gas comprising steam, thus producing a product stream which typically contains substantially equal levels of CO.sub.2 and H.sub.2S. The process further comprises a step (c) of regenerating the purged adsorbent by removal of water. The adsorbent comprises alumina and one or more alkali metals, such as potassium oxides, hydroxide or the like.

Catalyst compositions, articles, systems and methods related to a three-way-catalyst composition comprising alumina doped with a transition metal.

The present invention provides a catalyst for the decomposition of nitrous oxide, said catalyst comprising oxides of cobalt, zinc and aluminum and an alkali metal promoter.

[Summary]

[Problem]

The problem addressed by the present invention lies in providing an exhaust gas purification filter which can efficiently treat particulate matter in exhaust gas.

[Solution]

The present invention provides an exhaust gas purification filter including a substrate comprising a plurality of porous partitions, wherein the partitions form an exhaust gas flow path, a porous catalytic layer is provided on the partitions and the catalytic layer having a thickness of 10 μm or greater is provided over at least 20% of the total length of the partitions in the lengthwise direction thereof, and the catalytic layer having a thickness of 10 μm or greater is not present on the partitions 15 mm from an outflow side.