The present disclosure generally provides catalysts, catalytic articles and catalyst systems including such catalytic articles. In particular, the catalyst composition includes a zeolite having a chabazite (CHA) crystal structure ion-exchanged with iron and copper. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems containing a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant.

Hydrocarbon (HC) traps are disclosed. The HC trap may include a first zeolite material having an average pore diameter of at least 5.0 angstroms and configured to trap hydrocarbons from an exhaust stream and to release at least a portion of the trapped hydrocarbons at a temperature of at least 225 C. The HC trap may also include a second zeolite material having an average pore diameter of less than 5.0 angstroms or larger than 7.0 angstroms. One or both of the zeolite materials may include metal ions, such as transition, Group 1A, or platinum group metals. The HC trap may include two or more discrete layers of zeolite materials or the two or more zeolite materials may be mixed. The multiple zeolite HC trap may form coke molecules having a relatively low combustion temperature, such as below 500 C.

A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.

A method includes: providing a SCR system comprising a SCR catalyst; heating the SCR system to a temperature greater than 500 degrees Celsius for a predetermined time so as to increase sulfur resistance of the SCR catalyst; and installing the SCR system in an aftertreatment system.

Provided is an exhaust gas purification catalyst that purifies nitrogen oxides, comprising a catalyst support and cerium oxide loaded thereon, wherein the catalyst support contains: at least one of zeolite selected from the group consisting of chabazite, SAPO-34 and SSZ-13, and 1 wt % to 10 wt % wt % of copper, iron or a mixture thereof based on the weight of the catalyst; and the amount of the cerium oxide is 1 wt % to 30 wt % based on the weight of the catalyst, and the cerium oxide has a crystallite diameter of 0.1 nm to 2.5 nm.

An exhaust gas purifying catalyst includes an inlet-side catalyst layer formed on an inner side of the partition wall from a surface of the partition wall in contact with an inlet-side cell and formed along an extension direction from an end portion on the exhaust gas inflow side, and an outlet-side catalyst layer formed on the inner side of the partition wall from a surface of the partition wall in contact with an outlet-side cell and formed along the extension direction from an end portion on the exhaust gas outflow side. Here, a sum of the lengths of the inlet-side catalyst layer and the outlet-side catalyst layer is larger than the entire length of the partition wall, and a total amount of an SCR catalyst body present in the outlet-side catalyst layer is larger than a total amount of an SCR catalyst body present in the inlet-side catalyst layer.

Disclosed is a reactive filter, that is a selective catalytic reduction filter or an oxidative reaction filter, including a porous substrate including internal pores having their inner surface, totally or partially, directly coated with a catalytic zeolite material resulting from an in situ hydrothermal synthesis. Also disclosed is a process for preparing such a reactive filter and the use thereof in an engine exhaust depolluting system.

A coated monolith article for the treatment of an exhaust gas is obtainable by the method comprising: providing a porous monolith article comprising a plurality of channels for passage of an exhaust gas, each channel having a gas-contacting surface; spraying onto the gas-contacting surface, as a dry particulate aerosol, inorganic particles and a silicone resin to form a coating layer; and calcining the coating layer to provide a coated monolith article.

An uncalcined monolith article comprises a dry particulate composition comprising inorganic particles and a silicone resin. The uncalcined monolith article can be prepared by spraying, as a dry particulate aerosol, inorganic particles and a silicone resin on a monolith article to form a coating layer.

The present invention relates to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO.sub.2 and X.sub.2O.sub.3, wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO.sub.2, one or more sources for X.sub.2O.sub.3, one or more tetraalkylammonium cation R.sup.1R.sup.2R.sup.3R.sup.4N.sup.+-containing compounds, and one or more tetraalkylammonium cation R.sup.5R.sup.6R.sup.7R.sup.8N.sup.+-containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, and R.sup.7 independently from one another stand for alkyl, and wherein R.sup.8 stands for cycloalkyl, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.