A composition and method for producing the same are provided. The composition includes transition metal oxides adhered to a surface of a cerium oxide support, and can additionally include alkali metal or alkaline earth metal promotors. The method includes incipient wetness impregnation of the support with metal salt in solution, and can include impregnation with a metal chelator salt. The composition can be useful as a catalyst for the reduction of noxious gases in combustion exhaust streams. The composition can be of particular use as a component of an automobile catalytic converter, for the specific catalytic reduction of nitrogen oxides to nitrogen gas.

Embodiments of the present disclosure are directed towards methods for preparing mixed-metal oxide particles by heating adamantane-intercalated layered double-hydroxide (LDH) particles at a reaction temperature of from 400° C. to 800° C. to form mixed-metal oxide particles. The adamantane-intercalated LDH particles have a general formula [M.sub.1-xAl.sub.x(OH).sub.2](A).sub.x.mH.sub.2O, where x is from 0.14 to 0.33, m is from 0.33 to 0.50, M is chosen from Mg, Ca, Co, Ni, Cu, or Zn, and A is adamantane carboxylate, and an aspect ratio greater than 100. The aspect ratio is defined by the width of an adamantane-intercalated LDH particle divided by the thickness of the adamantane-intercalated LDH particle. The mixed-metal oxide particles comprise a mixed-metal oxide phase containing M, Al or Fe, and carbon.

Described is a selective catalytic reduction material comprising a spherical particle including an agglomeration of crystals of a molecular sieve. The catalyst is a crystalline material that is effective to catalyze the selective catalytic reduction of nitrogen oxides in the presence of a reductant at temperatures between 200° C. and 600° C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

Catalytic articles having a high porosity substrate containing platinum, palladium or a mixture thereof, in walls of the high porosity substrate and an SCR catalyst coating on a wall of the high porosity substrate are disclosed. The platinum, palladium or mixture thereof can be present in the wall of the high porosity support as a metal, or as a supported platinum, palladium or a mixture thereof. The catalytic articles are useful for selective catalytic reduction (SCR) of NOx in exhaust gases and in reducing the amount of ammonia slip. Methods for producing such articles are described. Methods of using the catalytic articles in an SCR process, where the amount of ammonia slip is reduced, are also described.

Provided is a nitrogen oxide (NO.sub.X) reduction catalyst including an active site including at least one of a metal vanadate expressed by [Chemical Formula 1] and a metal vanadate expressed by [Chemical Formula 2], and a support for loading the active site thereon.
(M.sub.1).sub.XV.sub.2O.sub.X+5  [Chemical Formula 1] (where M.sub.1 denotes one selected from among manganese (Mn), cobalt (Co), and nickel (Ni), and X denotes a real number having a value between 1 and 3.)
(M.sub.2).sub.YVO.sub.4  [Chemical Formula 2] (where M.sub.2 denotes one selected from among lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and Y denotes a real number having a value between 0.5 and 1.5).

Embodiments of the invention include a filtration element. In an embodiment, the invention includes a filtration element for an airplane cabin that includes a first media portion upstream from a second media portion. The first media portion can include activated carbon. The second media portion can include a catalyst material. Other embodiments are also included herein.

The present invention relates to a VOC reduction system and a VOC reduction method that applies pulse type thermal energy to a catalyst to activate the catalyst and oxidizes and removes the VOC.

A catalyst for adsorbing hydrocarbon includes a first catalyst configured to adsorb short-chain hydrocarbons and including zeolites having a pore size of about 0.30 nm to about 0.44 nm and a second catalyst configured to adsorb a long-chain hydrocarbon and including zeolites ion-exchanged with a transition metal. The catalyst can be coated on a substrate of a hydrocarbon trap.

A propane gas-utilizing system includes a housing having propane gas and a propane leakage prevention material having a catalyst, scavenger, and/or oxidizer of the propane gas arranged in the housing and including at least one of (a) an oxide material having at least one composition of formula (I): Ru.sub.1-xM.sub.xO.sub.2 (I), where 0<x≤0.1 and M is Ag, K, Pt, Rh, or Ir, or (b) an oxide material having at least one composition of formula (II): Co.sub.3-xM.sub.xO.sub.4 (II), where 0<x≤0.3, and M is Pd, Cu, or Sr, or (c) an oxide material having at least one composition of formula (III): MM′.sub.xO.sub.y (III), where x is a stoichiometric ratio of M′ to M, 0≤x≤1.5, y is a stoichiometric ratio of O to M, 1≤y≤3, M is an alkali metal, and M′ (if x>0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr.

The present invention discloses a method of preparing a catalyst for low-temperature synergistic catalytic purification of NO.sub.x and HCN in a flue gas, and the use thereof. Citric acid is dissolved in ethanol to obtain a citric acid/ethanol solution; tetrabutyl titanate is added, mixed uniformly to obtain a tetrabutyl titanate-citric acid/ethanol solution; glacial acetic acid is added dropwise to react for 30-40 min to obtain a solution A; the metal salt solution was added dropwise into the solution A, mixed uniformly and added with nitric acid, ammonium hydroxide is added dropwise to adjust the pH value, and the temperature is raised at a constant speed to obtain a gel B; dried and then then baked at a temperature of 300-500° C. for 3-4 h, cooled in the furnace, pulverized, tableted and sieved to obtain the catalyst for the low-temperature synergistic catalytic purification of NO.sub.x and HCN in the flue gas.