An exhaust gas cleaner constituted by a first catalyst comprising a first porous inorganic oxide supporting an Ag component, a W component and a Pt component and optionally a second catalyst comprising a second porous inorganic oxide supporting a Pt component alone or in combination with a W component. The Ag component may include Ag and compounds thereof, the Pt component of the first and second catalysts may include Pt, Pd, Ru, Rh, Ir and Au, and the W component of the first and second catalysts may include W, V, Mn, Mo, Nb and Ta. The W component effectively catalyze the reduction of nitrogen oxides by ammonia to enhance the removal efficiency of the exhaust gas cleaner.

Exhaust gas cleaner and method for cleaning exhaust gas

Compositions and method for destroying biological agents such as toxins are provided wherein the substance to be destroyed is contacted with finely divided metal oxide nanocrystals. In various embodiments, the metal oxide nanocrystals have reactive atoms stabilized on their surfaces, species adsorbed on their surfaces, or are coated with a second metal oxide. The desired metal oxide nanocrystals can be pressed into pellets for use when a powder is not feasible. The methods of the invention are safe for humans, equipment, and the environment, and provide for decontamination of warfare sites, of equipment exposed to the contaminant, and of soil, water, and air having been exposed to the contaminant. Preferred metal oxides for the methods include MgO, CaO, TiO2, ZrO2, FeO, V2O3, V2O5, MN2O3, Fe2O3, NiO, CuO, Al2O3, ZnO, and mixtures thereof. Preferred coating metal oxides include oxides of metals selected from the group consisting of Ti, V, Fe, Cu, Ni, Co, Mn, Zn, and mixtures thereof. Preferred reactive atoms include halogens and Group I metals, and preferred species include SO2, NO2, and ozone.

Reactive nanoparticles as destructive adsorbents for biological and chemical contamination

A method is provided for destroying a target component, such as hydrocarbons, halogenated hydrocarbons, diethyl-4-nitrophenylphosphate (paraoxon), 2-chloroethyl ethyl sulfide (2-CEES), dimethylmethylphosphonate (DMMP), bacteria such as Bacillus Cereus, Bacillus Globigii, Chlamydia and/or Rickettsiae, fungi and viruses, by contacting the target component with an adsorbent such as MgO, CaO, TiO 2 , ZrO 2 , FeO, V 2 O 5 , V 2 O 3 , Mn 2 O 3 , Fe 2 O 3 , NiO, CuO, Al 2 O 3 , ZnO and mixtures thereof wherein the adsorbent contains either reactive atoms selected from the group consisting of halogens and alkali metals stabilized on the surfaces of the adsorbent or ozone and wherein the contacting is conducted at a temperature of -40 to 600° C. for a time period of at least about 4 seconds. The adsorbent may be in the form of solids having a size of about 3 to 20 nanometers or in the form of pellets having a size of at least 1 millimeter.

Nanoparticles for the destructive sorption of biological and chemical contaminants

The present invention is directed to methods for reducing SOx, NOx, and CO emissions from a fluid stream comprising contacting said fluid stream with a compound comprising magnesium and aluminum and having an X-ray diffraction pattern displaying at least a reflection at a two theta peak position at about 43 degrees and about 62 degrees, wherein the ratio of magnesium to aluminum in the compound is from about 1:1 to about 10:1. In one embodiment, the ratio of magnesium to aluminum in the compound is from about 1:1 to about 6:1. In one embodiment, the ratio of magnesium to aluminum in the compound is from about 1.5:1 to about 10:1. In another embodiment, the invention is directed to methods wherein the ratio of magnesium to aluminum in the compound is from about 1.5:1 to about 6:1.

Mixed metal oxide sorbents

Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in an amount larger than its stoichiometric amount relative to unburned components in the exhaust gas, by (i) disposing an exhaust gas cleaner in a flow path of the exhaust gas, the exhaust gas cleaner comprising 0.2-15 weight % (on a metal basis) of fine silver or silver oxides having an average diameter of 10-1,000 nm and supported on a porous inorganic oxide; (ii) introducing hydrocarbons and/or oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 200°-600° C., thereby causing a reaction of nitrogen oxides with the hydrocarbons and/or oxygen-containing organic compounds.

Exhaust gas cleaner and method for removing nitrogen oxides

Toxic substances contained in exhaust gases, especially nitrogen oxides contained in exhaust gases from automobiles, can be effectively eliminated, even in the presence of oxygen, by contacting such exhaust gases with a catalyst composition comprising iron or iron oxide, silver or silver oxide, at least a member selected from the group consisting of copper, beryllium, zinc, lead, indium, lanthanum, cerium and oxides of these metals, and a carrier. Especially good results can be obtained by employing a catalyst composition obtained by treating a composition comprising iron or iron oxide, silver or silver oxide, copper or copper oxide and a carrier with hydrogen sulfide, or by employing a catalyst composition comprising sulfides of iron, silver and copper supported on a carrier.

S Watanabe

Papers

Method for eliminating nitrogen oxides and catalyst composition for use in practicing said method