An oxidation catalyst is described for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a substrate; a first washcoat region disposed on the substrate, wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region adjacent to the first washcoat region, wherein the second washcoat region comprises a second platinum group metal (PGM) and a second support material; a third washcoat region disposed on the substrate, wherein the third washcoat region comprises a third platinum group metal (PGM) and a third support material; and wherein either: (i) the third washcoat region is adjacent to the second washcoat region; or (ii) the second washcoat region is disposed or supported on the third washcoat region. Also described are uses and methods involving the oxidation catalyst.

An oxidation catalyst is described for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a substrate; a first washcoat region disposed on the substrate, wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region adjacent to the first washcoat region, wherein the second washcoat region comprises a second platinum group metal (PGM) and a second support material; a third washcoat region disposed on the substrate, wherein the third washcoat region comprises a third platinum group metal (PGM) and a third support material; and wherein either: (i) the third washcoat region is adjacent to the second washcoat region; or (ii) the second washcoat region is disposed or supported on the third washcoat region. Also described are uses and methods involving the oxidation catalyst.

Provided is an electrode catalyst in which the contents of chlorine (Cl) species and bromine (Br) species are reduced to a predetermined level or lower, capable of exhibiting sufficient catalyst performance. The electrode catalyst has a core-shell structure including a support, a core part formed on the support and a shell part formed to cover at least a part of the surface of the core part. A concentration of bromine (Br) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 400 ppm or less, and a concentration of chlorine (Cl) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 900 ppm or less.

Provided is an electrode catalyst in which the contents of chlorine (Cl) species and bromine (Br) species are reduced to a predetermined level or lower, capable of exhibiting sufficient catalyst performance. The electrode catalyst has a core-shell structure including a support, a core part formed on the support and a shell part formed to cover at least a part of the surface of the core part. A concentration of bromine (Br) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 400 ppm or less, and a concentration of chlorine (Cl) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 900 ppm or less.

An exhaust gas control system includes an upstream purification device disposed in an exhaust passage of the internal combustion engine, a downstream purification device disposed in a portion of the exhaust passage downstream from the upstream purification device, a fuel addition valve disposed in a portion of the exhaust passage upstream from the upstream purification device, and a urea addition valve disposed in a portion of the exhaust passage between the upstream purification device and the downstream purification device, and a cooling device. The cooling device is configured such that refrigerant cools the fuel addition valve first and then cools the urea addition valve subsequent to the fuel addition valve.

An exhaust gas control system includes an upstream purification device disposed in an exhaust passage of the internal combustion engine, a downstream purification device disposed in a portion of the exhaust passage downstream from the upstream purification device, a fuel addition valve disposed in a portion of the exhaust passage upstream from the upstream purification device, and a urea addition valve disposed in a portion of the exhaust passage between the upstream purification device and the downstream purification device, and a cooling device. The cooling device is configured such that refrigerant cools the fuel addition valve first and then cools the urea addition valve subsequent to the fuel addition valve.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and met-al compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter includes a combined SCR and oxidation catalyst being arranged on the dispersion side and within wall of the filter; and a palladium including catalyst arranged on the permeation side and within wall of the filter facing the permeation side.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and met-al compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter includes a combined SCR and oxidation catalyst being arranged on the dispersion side and within wall of the filter; and a palladium including catalyst arranged on the permeation side and within wall of the filter facing the permeation side.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.

Ceramic candle filter and use of the filter in the removal of particulate matter in form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, the filter comprises a combined SCR and oxidation catalyst arranged at least on the dispersion side and/or within wall of the filter, the combined SCR and oxidation catalyst comprises palladium, a vanadium oxide and titania.