B01D2255/40

SCR catalyst

The present invention relates to a catalyst comprising at least one oxide of vanadium, at least one oxide of tungsten, at least one oxide of cerium, at least one oxide of titanium and at least one oxide of niobium, and an exhaust system containing said oxides.

METHOD AND SYSTEM FOR PRE-PURIFICATION OF A FEED GAS STREAM

A system and method of pre-purification of a feed gas stream is provided that is particularly suitable for pre-purification of a feed air stream in cryogenic air separation unit. The disclosed pre-purification systems and methods are configured to remove substantially all of the hydrogen, carbon monoxide, water, and carbon dioxide impurities from a feed air stream and is particularly suitable for use in a high purity or ultra-high purity nitrogen plant. The pre-purification systems and methods preferably employ two or more separate layers of hopcalite catalyst with the successive layers of the hopcalite separated by a zeolite adsorbent layer that removes water and carbon dioxide produced in the hopcalite layers.

INHIBITION-FREE LOW-TEMPERATURE ENGINE EXHAUST OXIDATION CATALYST

The present disclosure provides a method for preparing a supported metal alloy catalyst for low temperature engine exhaust oxidation without CO or NO inhibition. The catalyst includes bimetallic PdCu alloy deposited on a SiO.sub.2 support using the strong electrostatic adsorption method. The PdCu catalyst may be combined with a traditional PGM-based automotive oxidation catalyst in a series or dual-bed configuration. The first stage of the dual-bed system includes the PdCu catalyst, with the primary role of oxidizing CO at low temperature; the PGM-based catalyst in the second stage then oxidizes NO and hydrocarbons in the absence of any CO-inhibition effects.

METHOD FOR THE TREATMENT OF AN EXHAUST GAS AND AN HVAC SYSTEM
20230074001 · 2023-03-09 ·

The present invention relates to a method for the treatment of an exhaust gas comprising carbon monoxide (CO) and/or one or more volatile organic compounds (VOCs) using a PGM-free catalyst article comprising a mixed oxide of Mn, Cu, Mg, Al and La. The present invention also relates to an HVAC system comprising a PGM-free catalyst article.

Method for Improving Resistance to Sulfur-Poisoning Through Structural Transformation of Nano-Ceria Supported on Alumina
20230072800 · 2023-03-09 ·

An embodiment ceria-alumina support (CeO.sub.2—Al.sub.2O.sub.3 support) includes a nano-ceria having a shape of a polygonal bipyramid or a truncated polygonal bipyramid supported on alumina. An embodiment noble metal catalyst for treating exhaust gas includes a noble metal deposited on a ceria-alumina support (CeO.sub.2—Al.sub.2O.sub.3 support) that includes a nano-ceria having a shape of a polygonal bipyramid or a truncated polygonal bipyramid supported on alumina. An embodiment method for affecting resistance to sulfur-poisoning of a noble metal catalyst through structural transformation of nano-ceria supported on alumina includes performing a hydrothermal treatment of ceria supported on γ-alumina.

Tail gas treatment catalyst, preparation method therefor and use thereof

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

Powdered titanium oxide, method for the production thereof, and use thereof

A powdered catalyst material on a titanium oxide basis. The powdered catalyst material includes a combined content of at least 90 wt.-% of a hydrated titanium oxide having the general formula TiO.sub.(2-x)(OH).sub.2x, with 0<x≤1, (calculated as TiO.sub.2), and a silicon dioxide and hydrated precursors of the silicon dioxide (calculated as SiO.sub.2). A weight ratio of TiO.sub.2/SiO.sub.2, determined for TiO.sub.2 and SiO.sub.2 respectively, is at least 3 and less than 30. The wt.-% is based on a total weight of the catalyst material after the catalyst material has been dried at 105° C. for at least 2 hours. The powdered catalyst material has a specific surface area of >300 m.sup.2/g and an isoelectric point of from 4.0 to 7.0.

Manganese-cobalt spinel oxide nanowire arrays
11623206 · 2023-04-11 · ·

Manganese-cobalt (Mn—Co) spinel oxide nanowire arrays are synthesized at low pressure and low temperature by a hydrothermal method. The method can include contacting a substrate with a solvent, such as water, that includes Mn04- and Co2 ions at a temperature from about 60° C. to about 120° C. The method preferably includes dissolving potassium permanganate (KMn04) in the solvent to yield the Mn04- ions. the substrate is The nanoarrays are useful for reducing a concentration of an impurity, such as a hydrocarbon, in a gas, such as an emission source. The resulting material with high surface area and high materials utilization efficiency can be directly used for environment and energy applications including emission control systems, air/water purifying systems and lithium-ion batteries.

SELECTIVE CATALYTIC REDUCTION CATALYST COMPOSITION, CATALYTIC ARTICLE COMPRISING THE SAME AND METHOD FOR PREPARING THE CATAYTIC ARTICLE
20220331782 · 2022-10-20 ·

The present invention relates to a catalyst composition comprising a support, catalytically active species comprising a vanadium species, an antimony species and a tungsten species, and optionally, at least one further species selected from the group consisting of silicon species, aluminum species, zirconium species, titanium species, and cerium species; a catalytic article comprising the same, a method for preparing the catalytic article, and use of the catalyst composition or the catalytic article for selective catalytic reduction of nitrogen oxides in exhaust gases.

Catalysts for NOx reduction and sulfur resistance
20220314166 · 2022-10-06 · ·

The present invention belongs to the technical field of functional organic macromolecule composite catalysts and involves the preparation of a nitrogen-doped lattice macromolecule composite loaded with an efficient denitrification and sulfur resistance catalyst, firstly using the method of adding metal salts to make a large amount of Ce.sup.3+, Ce.sup.4+, Sn.sup.3+ and Sn.sup.4+ ions accumulate around the cyanuric acid molecule. Afterwards, 2,4,6-triaminopyrimidine and cytosine were added to graft with the cyanuric acid to produce the N-doped macromolecule in the first stage. After that, potassium permanganate was used as the oxidizing agent, and redox reaction occurred on the surface of N-doped macromolecules, so that the manganese cerium tin catalyst was grown in situ on the surface of N-doped macromolecules, and finally calcined at once to cross-link the N-doped macromolecules to generate catalyst composites. The catalysts described in this invention have higher efficient NOx reduction and sulfur resistance performance.