The present invention relates to a compressed natural gas combustion and exhaust system comprising: (i) a natural gas combustion engine; and (ii) an exhaust treatment system, the exhaust treatment system comprising a intake for receiving an exhaust gas from the combustion engine and a catalyst article arranged to receive and treat the exhaust gas, wherein the catalyst article comprises: a substrate having at least first and second coatings, the first coating being free from platinum-group-metals and comprising a copper-containing zeolite having the CHA framework-type and the second coating comprising a palladium-containing zeolite, wherein the first coating is arranged to contact the exhaust gas before the second coating. The present invention further relates to a method and a use.

A method for producing a hydroisomerization catalyst includes a first step of preparing a support precursor by heating a mixture containing an ion-exchanged zeolite and a binder, the ion-exchanged zeolite being prepared by ion-exchanging an organic template-containing zeolite which contains an organic template and has a one-dimensional pore structure including a 10-membered ring in a solution containing ammonium ions and/or protons, at a temperature of 250 to 350° C. under N.sub.2 atmosphere, and a second step of preparing a hydroisomerization catalyst, which is prepared by calcining a catalyst precursor, the catalyst precursor being prepared based on the support precursor containing a platinum salt and/or a palladium salt, at a temperature of 350 to 400° C. in an atmosphere containing molecular oxygen, the hydroisomerization catalyst containing a support which includes a zeolite and carries platinum and/or palladium.

A method for producing a hydroisomerization catalyst includes a first step of preparing a support precursor by heating a mixture containing an ion-exchanged zeolite and a binder, the ion-exchanged zeolite being prepared by ion-exchanging an organic template-containing zeolite which contains an organic template and has a one-dimensional pore structure including a 10-membered ring in a solution containing ammonium ions and/or protons, at a temperature of 250 to 350° C. under N.sub.2 atmosphere, and a second step of preparing a hydroisomerization catalyst, which is prepared by calcining a catalyst precursor, the catalyst precursor being prepared based on the support precursor containing a platinum salt and/or a palladium salt, at a temperature of 350 to 400° C. in an atmosphere containing molecular oxygen, the hydroisomerization catalyst containing a support which includes a zeolite and carries platinum and/or palladium.

Zeolites having highly dispersed bimetallic clusters, uniformly distributed in size and composition, encapsulated therein are disclosed. Metal encapsulation and alloying is conferred by introducing ligated metal cation precursors into zeolite synthesis gels, which are subsequently crystallized hydrothermally to form zeolites with metal cations occluded in the pores. The ligated cations are anchored to the zeolite framework via siloxane bridges which enforces their uniform dispersion throughout the zeolite crystals. Treatment of the crystallized zeolites in O.sub.2 and then H.sub.2 forms bimetallic clusters, which remain narrowly distributed in size and composition.

An exhaust system for treating an exhaust gas from an internal combustion engine is disclosed. The system comprises a modified lean NO.sub.x trap (LNT), a urea injection system, and an ammonia-selective catalytic reduction catalyst. The modified LNT comprises a first layer and a second layer. The first layer comprises a NO.sub.x adsorbent component and one or more platinum group metals. The second layer comprises a diesel oxidation catalyst zone and an NO oxidation zone. The diesel oxidation catalyst zone comprises a platinum group metal, a zeolite, and optionally an alkaline earth metal. The NO oxidation zone comprises a platinum group metal and a carrier. The modified LNT stores NO.sub.x at temperatures below about 200° C. and releases at temperatures above about 200° C. The modified LNT and a method of using the modified LNT are also disclosed.

The present invention provides crystalline aluminosilicate zeolites having a maximum pore size of eight tetrahedral atoms, wherein the zeolite has a total proton content of less than 2 mmol per gram. The zeolite may comprise 0.1 to 10 wt.-% of at least one transition metal, calculated as the respective oxide and based on the total weight of the zeolite. It may furthermore comprise at least one alkali or alkaline earth metal in a concentration of 0 to 2 wt.-%, calculated as the respective metal and based on the total weight of the zeolite. The zeolites may be used for the removal of NOx from automotive combustion exhaust gases.

Catalysts and method of preparing the catalysts are disclosed. One of the catalysts includes a zeolite support, a Group VIII metal on the zeolite support, and at least two halides bound to the zeolite support, to the Group VIII metal, or to both, and can have an average crush strength greater than 11.25 lb based on at least two samples of pellets of the catalyst measured in accordance with ASTM D4179.

Catalysts and method of preparing the catalysts are disclosed. One of the catalysts includes a zeolite support, a Group VIII metal on the zeolite support, and at least two halides bound to the zeolite support, to the Group VIII metal, or to both, and can have an average crush strength greater than 11.25 lb based on at least two samples of pellets of the catalyst measured in accordance with ASTM D4179.

Process for catalytic oxidative removal of at least one oxidisable gaseous compound from a gas mixture comprising the at least one oxidisable gaseous compound as well as oxygen through the use of an oxidation catalyst, whereby the gas mixture is not a combustion flue gas, characterised in that the oxidation catalyst was produced through the use of at least one exothermic-decomposing platinum precursor.

This disclosure relates to new crystalline microporous solids (including silicate- and aluminosilicate-based solids), the compositions comprising 8 and 10 membered inorganic rings, particularly those having IWV topologies having a range of Si:Al ratios, methods of preparing these and known crystalline microporous solids using certain quaternized imidazolium cation templates.