The present invention relates to a process for preparing a catalyst for the selective catalytic reduction of nitrogen oxide comprising, among other steps, preparing a second aqueous mixture comprising water and an iron salt; and disposing the second mixture on the substrate obtained according to (ii), comprising a coating comprising a zeolitic material comprising copper, over y % of the substrate axial length from the inlet end to the outlet end of the substrate, wherein y is in the range of from 10 to x, obtaining a substrate comprising, in a first zone, the coating comprising a zeolitic material comprising copper and over y % of the substrate axial length an iron salt; and, if x > y, in a second zone extending from y % to x % of the substrate axial length from the inlet end to the outlet end, the coating comprising a zeolitic material comprising copper.

A method for evaluating a service interval for replacing a filter of a system for extracting an aqueous liquid from a motor vehicle tank in response to the risk of progressive clogging of said filter from use. A compound clogging risk decision value (K) is generated (320) on the basis of the sum of a plurality of elementary values (k1, k2, k3, k4) of the clogging risk, each related to a risk criterion depending on the operation of the extraction system since commissioning of the filter. The compound clogging risk decision value is compared (340) to a threshold value, and an alert to replace the filtration device is generated (351, 352) if the compound clogging risk value exceeds the threshold value.

The present disclosure relates to a method for forming a catalyst article comprising: (a) forming a plastic mixture having a solids content of greater than 50 % by weight by mixing together a crystalline small pore molecular sieve in an H.sup.+ or NH.sub.4.sup.+ form, iron sulphate, an inorganic matrix component, an organic auxiliary agent, an aqueous solvent and optionally inorganic fibres; (b) moulding the plastic mixture into a shaped article; and (c) calcining the shaped article to form a solid catalyst body. The present disclosure further relates to a catalyst article, an exhaust system, and a method of treating an exhaust gas.

Described are exhaust gas treatment systems for treatment of a gasoline engine exhaust gas stream. The exhaust gas treatment systems comprise an ammonia generating catalyst and an ammonia selective catalytic reduction (SCR) catalyst downstream of the ammonia generating catalyst. The ammonia generating catalyst comprises a NO.sub.x storage component, a refractory metal oxide support, a platinum component, and a palladium component. The ammonia generating catalyst is substantially free of ceria. The platinum and palladium components are present in a platinum to palladium ratio of greater than about 1 to 1.

Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.

The present invention provides an iron-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms and having the framework type CHA, AEI, AFX, ERI or LTA, wherein the iron (Fe) is present in a range of from about 0.5 to about 5.0 wt. % based on the total weight of the iron-loaded aluminosilicate zeolite, wherein an ultraviolet-visible absorbance spectrum of the iron-loaded synthetic aluminosilicate zeolite comprises a band at approximately 280 nm, wherein a ratio of an integral, peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for the band at approximately 280 nm to an integral peak-fitted ultraviolet-visible absorbance signal measured in arbitrary units (a.u.) for a band at approximately 340 nm is >about 2. The present invention further provides a method of making an metal-loaded aluminosilicate zeolite having a maximum pore opening defined by eight tetrahedral atoms from pre-existing aluminosilicate zeolite crystallites, wherein the metal is present in a range of from 0.5 to 5.0 wt. % based on the total weight of the metal-loaded aluminosilicate zeolite.

The present disclosure generally provides a catalyst composition comprising a zeolite containing iron and/or copper with a reduced amount of extra-framework aluminum. The catalyst composition is useful to catalyze the reduction of nitrogen oxides in exhaust gas in the presence of a reductant.

An exhaust treatment system for a work vehicle includes a selective catalytic reduction (SCR) system having an SCR outlet for expelling treated exhaust flow therefrom, a flow conduit in fluid communication with the outlet, an exhaust sensor positioned within the flow conduit downstream of the outlet, and a flow mixer positioned upstream of the exhaust sensor. The flow mixer has an end wall defining sector openings circumferentially extending between first and second sector sides and radially between radially inner and outer sector ends. Moreover, the flow mixer has swirler vanes, where each of the swirler vanes extends circumferentially from the first sector side of a respective one of the sector openings and radially between radially inner and outer vane ends. Particularly, the radially outer vane end of each of the swirler vanes is spaced apart from the radially outer sector end of the respective one of the sector openings.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of an ammonia-fueled engine, the emission treatment system including a selective catalytic reduction (SCR) catalyst disposed on a substrate in fluid communication with the exhaust stream, an oxidation catalyst disposed on a substrate positioned either upstream or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, and optionally, one or more adsorption components disposed on a substrate positioned upstream and/or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, the adsorption component chosen from low temperature NO.sub.x adsorbers (LT-NA), low temperature ammonia adsorbers (LT-AA), low temperature water vapor adsorbers (LT-WA), and combinations thereof. The disclosure further provides a related method of treatment of an exhaust gas.

A method of recovering catalyst performance includes providing a vanadium selective catalytic reduction (VSCR) catalyst. The method includes exposing the VSCR catalyst to a first humidity level in a range of 50%-100% relative humidity, at a first temperature in a range of 20° C.-100° C., for a first period of time of at least two hours. The method includes thermally treating the VSCR catalyst at a second temperature in a range of 300° C.-600° C. for a second period of time of at least than one hour.