The disclosure relates to a method for making a photocatalytic structure, the method comprising: providing a carbon nanotube structure comprising a plurality of carbon nanotubes intersected with each other; a plurality of openings being defined by the plurality of carbon nanotubes; forming a photocatalytic active layer on the surface of the carbon nanotube structure; applying a metal layer pre-form on the surface of the photocatalytic active layer; and annealing the metal layer pre-form.

An exhaust gas purification catalyst device including a substrate and an SCR catalyst layer on the substrate, the substrate containing catalyst precious metal particles directly supported on the substrate, the catalyst precious metal particles containing Pt, and the catalyst precious metal particles having an average particle diameter of 30 to 120 nm inclusive.

The present invention relates to a process for preparing a catalyst for the selective catalytic reduction of nitrogen oxide comprising, among other steps, preparing a second aqueous mixture comprising water and an iron salt; and disposing the second mixture on the substrate obtained according to (ii), comprising a coating comprising a zeolitic material comprising copper, over y % of the substrate axial length from the inlet end to the outlet end of the substrate, wherein y is in the range of from 10 to x, obtaining a substrate comprising, in a first zone, the coating comprising a zeolitic material comprising copper and over y % of the substrate axial length an iron salt; and, if x > y, in a second zone extending from y % to x % of the substrate axial length from the inlet end to the outlet end, the coating comprising a zeolitic material comprising copper.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

Methods for exhaust gas purification, including the steps of: attaching an exhaust gas purification catalyst to an exhaust system of an internal combustion engine, and supplying an exhaust gas to the exhaust gas purification catalyst, where the exhaust gas purification catalyst includes an upper layer containing first carrier particles which are particles of an inorganic oxide and rhodium, and a lower layer containing second carrier particles which are particles of an inorganic oxide, the upper layer includes a rhodium-rich portion near the surface of the upper layer on the upstream side of the exhaust gas flow, and the existence range of the rhodium-rich portion is in a range of greater than 50% to 80% of the length of the upper layer from a downstream side end of an exhaust gas flow and of less than 20 μm in the depth direction from an outermost surface of the upper layer.

A multilayer supported oxidative coupling of methane (OCM) catalyst composition (support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x/support; A is alkaline earth metal; Z is first rare earth element; E is second rare earth element; D is redox agent/third rare earth element; the first, second, third rare earth element are not the same; a=1.0; b=0.1-10.0; c=0.1-10.0; d=0-10.0; x balances oxidation states; first single oxide layer (Z.sub.b1O.sub.x1, b1=0.1-10.0; x1 balances oxidation states) contacts support and one or more mixed oxide layers; one or more mixed oxide layers (A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2, a2=1.0; b2=0.1-10.0; c2=0.1-10.0; d2=0-10.0; x2 balances oxidation states; A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x and A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2 are different) contacts first single oxide layer and optionally second single oxide layer, and second single oxide layer (AO), when present, contacts one or more mixed oxide layers and optionally first single oxide layer.

An exhaust gas control apparatus includes a honeycomb substrate and an inlet cell-side catalyst layer. The honeycomb substrate includes a porous partition wall that defines a plurality of cells extending from an inlet-side end face to an outlet-side end face. The cells include an inlet cell and an outlet cell that are adjacent to each other with the partition wall therebetween. The inlet cell is open at its inlet-side end and is sealed at its outlet-side end. The outlet cell is sealed at its inlet-side end and is open at its outlet-side end. The inlet cell-side catalyst layer is provided on a surface on the inlet cell side of the partition wall and extends from an inlet-side end of the partition wall. Porosity of the inlet cell-side catalyst layer is in a specific range.

The invention relates to a method for producing a wall-flow filter for removing fine particulate solids from gases, and to the use thereof for cleaning exhaust gases of an internal combustion engine. The invention also relates to a correspondingly produced exhaust-gas filter having a high filtration efficiency.

An object of the present invention is to provide a catalyst ensuring that when a gas-phase catalytic oxidation reaction of a material substance is conducted using a catalyst to produce a target substance, the pressure loss and coking are suppressed and the target substance can be produced in high yield. The present invention is related to a ring-shaped catalyst having a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

An exhaust gas purification device that allows suppressing an increase in pressure loss is provided. The exhaust gas purification device of the present disclosure includes a honeycomb substrate and an inflow cell side catalyst layer. The substrate includes a porous partition wall which defines inflow cells and outflow cells extending from an inflow side end to an outflow side end. The inflow cell side catalyst layer is disposed on a surface on the inflow cell side in an inflow cell side catalyst region from an inflow side end to a position close to an outflow side end of the partition wall. The permeability of a portion including an outflow side region from the position to the outflow side end of the partition wall is higher than a gas permeability of a portion including the inflow cell side catalyst region of the partition wall and the inflow cell side catalyst layer.