The infrared spectral performance of the N x O y species observed on oxide surfaces [N2O, NO−, NO, (NO)2, N2O3, NO+, NO2 − (different nitro and nitrito anions), NO2, N2O4, N2O5, NO2, and NO3 − (bridged, bidentate, and monodentate nitrates)] is considered. The spectra of related compounds (N2, H-, and C-containing nitrogen oxo species, C─N species, NH x species) are also briefly discussed. Some guidelines for spectral identification of N x O y adspecies are proposed and the transformation of the nitrogen oxo species on catalyst surfaces are regarded.

Identification of Neutral and Charged N x O y Surface Species by IR Spectroscopy

Automotive catalytic converters: current status and some perspectives

Catalytic removal of NO

This review covers the literature through 1991 on nitric oxide catalysis as applied to automobile exhaust systems. Attention is given to the threeway catalyst system which simultaneously promotes the reduction of nitrogen oxides and the oxidation of carbon monoxide and hydrocarbons. These systems have been used on most passenger cars in the United States since 1982. Prior to 1980, emission control catalysts were oxidation catalysts, and reduction in exhaust nitric oxide was achieved using engine modifications (i.e., exhaust gas recirculation). This review focuses on catalytic control of NO, for gasoline-fueled vehicles (not diesels and alternate fuels) and primarily on developments reported since 1982. The term NO, refers to both NO and NOz. The reader is referred to an earlier publication by the author for a general review of automobile catalytic converters [1] and to a review by Egelhoff [2] on the nitric oxide literature through 1980. The recent literature on NO, reduction in lean exhaust is c...

Nitric oxide catalysis in automotive exhaust systems

Catalysis for NOx abatement

PROBLEM TO BE SOLVED: To obtain a catalyst capable of highly efficiently reducing and removing NOx in a waste gas even in a wide temp. range even in the presence of excess oxygen and moisture by incorporating manganese oxide in a specific ratio in a proton-type zeolite by physical mixture. SOLUTION: Zeolite is made into proton-type by being ion-exchanged by communism ion and first, and the proton-type ZSM-5 is preferably used particularly and the manganese compound such as manganese nitrate is physically fixed with the proton-type zeolite by a precipitation method or the like using sodium carbonate as a precipitant. After that, the mixture is fired to make the manganese oxide content 1-40mass.%, preferably 2-30mass.% per the weight of the catalyst. The catalyst obtained in this way efficiently reduces and removes nitrogen oxide in the waste gas even in the presence of excess oxygen and water in the presence of hydrocarbons.

Nitrogen oxide catalytically reducing and removing catalyst and nitrogen oxide catalytically reducing and removing method

PURPOSE:To improve the selectivity of the titled compound such as ethanol, acetaldehyde, etc., in the reaction of carbon monoxide with hydrogen, economically, by using a catalyst comprising a combination of ruthenium with iridium. CONSTITUTION:The objective compound such as ethanol, acetaldehyde, acetic acid, etc. can be produced directly by the reaction of carbon monoxide with hydrogen in the presence of a catalyst comprising a combination of ruthenium with iridium, and if necessary with an alkaline earth metal or alkali metal, preferably lithium. The above catalyst can be prepared by dissolving ruthenium, iridium and if necessary lithium, etc. in water or an organic solvent such as n- hexane, alcohol, etc., adding a porous inorganic carrier to the solution, supporting the solute to the carrier by impregnation, ion exchange, etc., and fixing the metals to the carrier by reduction or heat-treatment.

Production of oxygen-containing c2 compound

PURPOSE:To improve the durability and life of a specific catalyst by using the specific catalyst and using DE lubricating oil having a specific ratio or below of the contents of an alkaline metal and alkaline earth metal and low- sulfurized DE fuel oil. CONSTITUTION:NOx is removed by bringing at least one of the catalysts among metal oxides consisting of alumina, titania, zirconia and zinc oxide or proton type zeolite or the catalysts formed by incorporating elements belonging to group VIIB, VIII, IB of periodic table therein or the catalysts formed by incorporating the perovskite type crystal structures of cobalt lanthanum trioxide and iron lanthanum trioxide therein or metallosilicate contg. B, P, Ga, Ti, Fe, Cu, Zn, Mo, La in zeolite aggregate lattice into contact with DE exhaust gases. The DE lubricating oil contg. =1 kinds among the alkaline metals and alkaline earth metals is used and the DE fuel oil contg. <=0.2wt.% sulfur content is used.

Method for removing nox in exhaust gas

PURPOSE:To remove nitrogen oxides in a waste gas by using a specific alumina catalyst in an oxidizing atmosphere in which excess oxygen is present in the presence of a hydrocarbon or an oxygen containing organic compound. CONSTITUTION:The specific alumina catalyst is used in the oxidizing atmosphere in which excess oxygen is present in the presence of the hydrocarbon or the oxygen containing organic compound. This catalyst is an alumina catalyst =0.26cm .g in the volume of narrow holes having .g in the volume of total narrow holes. At the time of bringing the waste gas containing nitrogen oxide into contact with the catalyst, NOx is removed at high percentage without reducing catalytic activity.

Mthod for removing nitrogen oxides

PURPOSE:To substantially improve NO decomposition activity by utilizing a metallic oxide catalyst incorporating a silver as a promoter in the metallic oxide catalyst decomposing NO contained in exhaust gas. CONSTITUTION:In a catalyst directly decomposing and reducing nitrogen oxide contained in exhaust gas, the metal oxide having NO decomposition activity, especially oxide of cobalt, iron or nickel is utilized as a main catalytic metal and silver is utilized as a promoter. The aq. soln. of a precipitant such as sodium carbonate is dropt into the mixed aq. soln. incorporating main catalytic metal and silver, and precipitate is prepared and separated. The catalyst obtained by such a way is substantially improved in NO decomposition activity and contributes to the clarification of the atmosphere.

Hamada Hideaki

Papers

Nitrogen oxide catalytically reducing and removing catalyst and nitrogen oxide catalytically reducing and removing method

Production of oxygen-containing c2 compound

Method for removing nox in exhaust gas

Mthod for removing nitrogen oxides

Decomposition catalyst for nitrogen oxide