Provided is a catalyst block for cleaning exhaust gas, having: a square-shaped honeycomb core provided with first-fourth outside surfaces; a first plate attached to the first outside surface; a second plate attached to the second outside surface; and an exterior frame disposed along the outer periphery of the firm and solid honeycomb core formed from the honeycomb core, the first plate and the second plate, the exterior frame being provided with a recessed part that at least encases the first plate, the second plate, the third outside surface and the fourth outside surface. In the catalyst block, a catalyst is supported in the honeycomb core, the first plate and the second plate, and the catalyst is not supported in the exterior frame.

Oxygen is effectively removed from hydrocarbon-containing gas streams while minimizing danger of explosion by contacting the gas stream with a catalyst comprising shaped bentonite supports having an outer shell containing catalytic metals gold, and at least one of palladium platinum, rhodium, or iridium.

A photocatalyst includes a composite fiber having at least two crystalline semi-conductors that provide a heterojunction structure in the composite fiber.

Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N.sub.2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings containing copper-containing molecular sieves disposed thereon, where for example a concentration of catalytic copper in an upstream zone is lower than the concentration of catalytic copper in a downstream zone.

A vehicle exhaust system is provided and comprises a catalyst positioned in an exhaust passage of a vehicle. The catalyst is in the form of a washcoat supported on a substrate. The system includes a phase change material located adjacent to the catalyst to maintain the temperature of the catalyst between engine shut-down and subsequent start-up as well as to regulate the temperature during engine operation. In some embodiments, the phase change material comprises particles of a metal or metal alloy encapsulated in a ceramic material. The metal or metal alloy is adapted to have a phase change that occurs within a temperature range wherein the catalyst is active.

A catalyst bed comprising a ceramic or metallic foam comprising one or more NOx reduction catalysts is described. Further, a method for reducing the concentration of NOx in a dust containing gas stream comprising: a) passing a first gas stream containing NOx into a contacting zone; b) contacting the first gas stream with a ceramic or metallic foam catalyst bed having one or more flow paths through the catalyst bed wherein the ceramic or metallic foam comprises a NOx reduction catalyst to produce a second gas stream with a reduced NOx concentration; and c) passing the second gas stream out of the contacting zone wherein the first gas stream has a dust concentration of at least 5 mg/Nm3 and the second gas stream comprises at least 50% of the amount of dust in the first gas stream.

A catalyst bed comprising a ceramic or metallic foam comprising one or more NO.sub.x reduction catalysts is described. A method for reducing the concentration of NO.sub.x in a dust containing gas stream comprising: a) passing a first gas stream containing NO.sub.x into a contacting zone; b) contacting the first gas stream with a ceramic or metallic foam catalyst bed having one or more flow paths through the catalyst bed wherein the ceramic or metallic foam comprises a NO.sub.x reduction catalyst to produce a second gas stream with a reduced NO.sub.x concentration; and c) passing the second gas stream out of the contacting zone wherein the first gas stream has a dust concentration of at least 5 mg/Nm.sup.3 and the pressure drop of the foam catalyst bed increases by 300% or less relative to the initial pressure drop of the foam catalyst bed due to dust accumulation, measured under the same conditions is also described.

A reactor for reducing the concentration of NO x in a stream comprising: an inlet for the stream; an outlet for a stream containing a reduced concentration of NOx; one or more catalyst beds comprising a ceramic or metallic foam with a NOx reduction catalyst; one or more flow paths from the inlet to the outlet that passes through at least one catalyst bed wherein the catalyst beds are closed at the top and bottom so that the flow path through the catalyst bed passes through the sides of the catalyst bed in a lateral flow is described.

A micro coil includes a micro coil body having heat resistance sufficient to keep the micro coil body from thermal decomposition and melting in a high-temperature environment, and a coating layer that is provided on a surface of the micro coil body, and has heat resistance and electrical conductivity under the high-temperature environment and an oxidizing atmosphere. The coating layer has a shape that causes induced current to be produced according to a magnetic-field component of radio waves, when the micro coil receives the radio waves.

Methods and systems are provided for detecting a missing exhaust catalyst based on water adsorption and related exothermic temperature rise by the catalyst. In one example, a method may include indicating an exhaust catalyst missing in response to an estimated exhaust temperature profile being different from an expected exhaust temperature profile. The estimated exhaust temperature profile may be based on exhaust temperature upstream and downstream of the catalyst.