The present disclosure features a method of making an engine aftertreatment catalyst, where the engine aftertreatment catalyst includes a metal oxide, a metal zeolite, and/or vanadium oxide when the metal oxide is different from vanadium oxide, each of which can be independently surface-modified with a surface modifier. The method includes providing a solution including an organic solvent and an organometallic compound; mixing the solution with a metal oxide, a metal zeolite, and/or a vanadium oxide to provide a mixture; drying the mixture; and calcining the mixture to provide a surface-modified metal oxide catalyst, a surface-modified metal zeolite catalyst, and/or a surface-modified vanadium oxide catalyst. The organometallic compound can be, for example, a metal alkoxide, a metal carboxylate, a metal acetylacetonate, and/or a metal organic acid ester.

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

Systems and methods for removal of gas phase contaminants may utilize catalytic oxidation. For example, a method may include passing a gas that includes a gas phase contaminant through a catalytic membrane reactor at a temperature of about 150 C. to about 300 C., wherein the catalytic membrane reactor includes a bundle of tubular inorganic membranes, wherein each of the tubular inorganic membranes comprise a macroporous tubular substrate with an oxidative catalyst and a microporous layer disposed on a bore side of the macroporous tubular substrate, and wherein at least about 50% of the gas flows through the tubular inorganic membranes in a Knudsen flow regime; and oxidizing at least some of the gas phase contaminant with the oxidative catalyst layer, thereby reducing a concentration of the gas phase contaminant in the gas.

The invention contributes to a cost effective way to solve the problem of trace ammonia removal from a hydrogen and nitrogen containing gas. The set of catalysts of the invention selectively oxidised ammonia in ppm concentration even in gas mixtures containing hydrogen gas in concentrations of three orders of magnitude higher than the concentration of ammonia.

A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NO.sub.x when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NO.sub.x when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NO.sub.x. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NO.sub.x emissions from a diesel engine, the NO.sub.x emissions including NO.sub.x emitted during a predetermined cold-start time period.

The purpose of the present invention is to provide an exhaust purifier (1) which is capable of restoring a pressure difference (P) and a purification rate (NOx removal efficiency) of a NOx catalyst (14) to the initial states thereof. An exhaust purifier (1) for removing particulate matter adhered to a NOx catalyst (14) by injecting pressurized air using an air injection nozzle (16) into a housing (13) of a catalyst reactor (12) in Which the NOx catalyst (14) serving as a catalyst is positioned, wherein the particulate matter is removed by increasing the pressure inside the catalyst reactor (12) to a prescribed pressure (IP) within a prescribed interval of time (t) by operating an injection valve (17) for supplying pressurized air

The invention provides processes for cleaning carbon dioxide-containing process gases from the preparation of vinyl acetate after reaction of ethylene with acetic acid and oxygen in heterogeneously catalyzed, continuous gas phase processes, characterized in that carbon dioxide-containing process gases, for removal of carbon dioxide, are contacted with one or more scrubbing solutions, and one or more scrubbing solutions comprise one or more oxides of metals (metal oxides) selected from the group comprising vanadium, niobium, tantalum, chromium, molybdenum, manganese and arsenic.

An ammonia slip control catalyst having a layer containing perovskite and a separate layer containing an SCR catalyst is described. The ammonia slip catalyst can have two stacked layers, with the top overlayer containing an SCR catalyst, and the bottom layer containing a perovskite. The ammonia slip catalyst can alternatively be arranged in sequential layers, with the SCR catalyst being upstream in the flow of exhaust gas relative to the perovskite. A system comprising the ammonia slip catalyst upstream of a PGM-containing ammonia oxidation catalyst and methods of using the system are described. The system allows for high ammonia oxidation with good nitrogen selectivity. Methods of making and using the ammonia slip catalyst to reduce ammonia slip and selectively convert ammonia to N.sub.2 are described.

The present disclosure features a method of making an engine aftertreatment catalyst, where the engine aftertreatment catalyst includes a metal oxide, a metal zeolite, and/or vanadium oxide when the metal oxide is different from vanadium oxide, each of which can be independently surface-modified with a surface modifier. The method includes providing a solution including an organic solvent and an organometallic compound; mixing the solution with a metal oxide, a metal zeolite, and/or a vanadium oxide to provide a mixture; drying the mixture; and calcining the mixture to provide a surface-modified metal oxide catalyst, a surface-modified metal zeolite catalyst, and/or a surface-modified vanadium oxide catalyst. The organometallic compound can be, for example, a metal alkoxide, a metal carboxylate, a metal acetylacetonate, and/or a metal organic acid ester.

Catalytic cores for a wall-flow filter include juxtaposed channels extending longitudinally between an inlet side and an outlet side of the core, wherein the inlet channels are plugged at the outlet side and outlet channels are plugged at the inlet side. Longitudinal walls forming the inlet and outlet channels separate the inlet channels from the outlet channels. The walls include pores that create passages extending across a width of the walls from the inlet channels to the outlet channels. Catalysts are distributed across the width and length of the walls within internal surfaces of the pores in a manner such that the loading of each catalyst across the width varies by less than 50% from an average loading across the width.