A process and an apparatus for gas denitration, involving first the use of an oxidizing agent to oxidize NO in a gas to NO.sub.2, then using a denitration agent to absorb the NO.sub.2 in the gas, thus achieving the purpose of denitration.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

A sorbent composition that is useful for injection into a flue gas stream of a coal burning furnace to efficiently remove mercury from the flue gas stream. The sorbent composition may include a sorbent with an associated ancillary catalyst component that is a catalytic metal, a precursor to a catalytic metal, a catalytic metal compound or a precursor to a catalytic metal compound. Alternatively, a catalytic metal or metal compound, or their precursors, may be admixed with the coal feedstock prior to or during combustion in the furnace, or may be independently injected into a flue gas stream. A catalytic promoter may also be used to enhance the performance of the catalytic metal or metal compound.

Cu-exchanged zeolite catalysts with a chabazite structure containing selected concentrations of alkali ions or alkaline-earth ions and a lower concentration of (Cu) ions are described and a sequential process for making. Catalysts of the present invention reduce light-off temperatures providing enhanced low-temperature conversion of NOx gases. Catalysts of the present invention also exhibit high selectivity values compared to conventional NOx reduction catalysts.

A method of utilizing a catalyst for the sterilization, disinfection and purification of indoor air. The catalyst carrier is made of inorganic porous material such as Silica, Zeolite, Diatomite, Sepiolite, Montmoroillonite, and Aluminum oxide. The catalyst carrier can also be made of Cordierite, or Mullite ceramic honeycomb. After dipping into stabilized sodium hypochlorite solution or stabilized chlorine dioxide solution, the catalyst is produced after dehydration. The catalyst is irradiated with ultraviolet lamp to generate gas-phase free radicals including reactive particles such as .OH, .ClO2, .HO2, .O, thereby sterilizing microbial air pollutants such as viruses, bacteria, fungi and other microorganisms, and remove chemical air pollutants such as formaldehyde.

A high-temperature NOx occlusion reduction type catalyst in which an NOx occlusion material containing an alkali metal is supported, and a low-temperature NOx occlusion reduction type catalyst in which an NOx occlusion material containing an alkaline earth metal is supported, are disposed in series on an upstream side and a downstream side, respectively, of an exhaust gas purification system. An oxidation catalyst is disposed on an upstream side of the high-temperature NOx occlusion reduction type catalyst. The desulfurization of the NOx occlusion reduction type catalysts is facilitated, and the NOx reduction efficiency is improved by the partial oxidation of hydrocarbons in the exhaust gas, while a wide NOx active temperature window is achieved.

A gasoline engine having an exhaust system comprises means for trapping particulate matter (PM) from the exhaust gas and a catalyst for catalysing the oxidation of the PM by carbon dioxide and/or water in the exhaust gas, which catalyst comprising a supported alkali metal. The invention further includes a method of combusting PM from a gasoline engine in CO.sub.2 and/or H.sub.2O from the exhaust gas at temperatures in excess of 500 C., which method comprising trapping the PM and contacting it with a catalyst comprising a supported alkali metal.

A material is described of formula Na.sub.xM.sub.yAl.sub.aSi.sub.bO.sub. with Face Centered Cubic (fcc) lattices forming F-4 3 m cubic structure, wherein M is at least one of lithium, potassium, rubidium, caesium, vanadium, chromium, iron, cobalt, nickel, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold, and cerium; 0<x+y22/3; wherein when y=0, 4<x/3, when 0<y/3, 0x<22/3, and when M is potassium, x>0; 1a3; 1b3; and 0<32/3. An exhaust gas system comprising the material and a method are also described herein.

An exhaust system for an internal combustion engine is disclosed. The exhaust system comprises a particulate filter, one or more NO.sub.x reduction catalysts, and a low pressure exhaust gas recirculation (EGR) circuit for connecting the exhaust system downstream of the filter and the one or more NO.sub.x reduction catalysts to an intake of the engine. The EGR circuit comprises a N.sub.2O-producing catalyst.

A method of preparing a catalyst composition suitable for removing sulfur from a catalytic reduction system and the catalyst composition prepared by the method are provided. The method of preparation of a catalyst composition, comprises: combining a metal oxide precursor, a catalyst metal precursor and an alkali metal precursor in the presence of a templating agent; hydrolyzing and condensing to form an intermediate product that comprises metal oxide, alkali metal oxide, and catalyst metal; and calcining to form a templated amorphous metal oxide substrate having a plurality of pores wherein the alkali metal oxide and catalyst metal are dispersed in an intermixed form in the metal oxide substrate.