An object of the present invention is to provide an exhaust gas purification catalyst including a wall-flow substrate and a catalyst layer, and having an improved exhaust gas purification performance, and, in order to achieve such an object, the present invention provides an exhaust gas purification catalyst including: a wall-flow substrate, first catalyst layers; and second catalyst layers; wherein the first catalyst layers and the second catalyst layers satisfy the following expressions (1) to (3):

L1<L2  (1)

T1<T2  (2)

WC1>WC2  (3)

wherein L1 represents the length of the first catalyst layers, L2 represents the length of the second catalyst layers, T1 represents the thickness of the rising portions of the first catalyst layers, T2 represents the thickness of the rising portions of the second catalyst layers, WC1 represents the mass of the first catalyst layers per unit volume of the portion of the substrate provided with the first catalyst layers, and WC2 represents the mass of the second catalyst layers per unit volume of the portion of the substrate provided with the second catalyst layers.

The invention relates to a wire made of platinum group metals for producing grid catalysts comprising platinum and rhodium. The invention is characterized in that the wire is made as a sheathed wire and consists of a core and one or more sheaths arranged one over the other outwards from the core in a radially symmetrical manner, and the rhodium concentration in the outermost sheath is lower than the rhodium concentration in the sheath or core arranged directly under the outermost sheath.

The present invention relates to systems and methods for catalytic removal of oxidized contaminants (for example, nitrite, chromate, chlorate, trichloroethene, CFC-11, 4-nonylphenol, RDX, and perfluorooctanoate) from water and wastewater. In some aspects, the catalytic method of removing oxidized contaminants comprises using precious metal nanoparticles as catalysts to reduce the oxidized contaminants.

The present invention relates to systems and methods for catalytic removal of oxidized contaminants (for example, nitrite, chromate, chlorate, trichloroethene, CFC-11, 4-nonylphenol, RDX, and perfluorooctanoate) from water and wastewater. In some aspects, the catalytic method of removing oxidized contaminants comprises using precious metal nanoparticles as catalysts to reduce the oxidized contaminants.

The problem to be solved by the present invention is to provide an oxygen storage and release material comprising a ceria-zirconia-based complex oxide improved in ability to remove HC and NOx and a three-way catalyst able to reduce an amount of NOx emission. Further, to solve this problem, an oxygen storage and release material comprising a ceria-zirconia-based complex oxide containing Gd.sub.2O.sub.3 in 0.1 mol % or more and less than 20 mol % and having an ion conductivity of 2×10.sup.−5 S/cm or more at 400° C. is provided. Further, in addition to the above, an oxygen storage and release material having a molar ratio of cerium and zirconium of 0.2 or more and 0.6 or less by cerium/(cerium+zirconium) and an speed of oxygen storage and release “Δt.sub.50” of 20.0 seconds or more or amount of oxygen storage and release of 300 μmol-O.sub.2/g or more etc. was obtained. Further, by applying the oxygen storage and release material to the catalyst, it is possible to assist the purification of exhaust gas as it changes every instant in accordance with the driving conditions and possible to obtain a catalyst with a higher ability to remove harmful components of catalytic precious metals than before. In particular, it is possible to obtain an automotive exhaust gas purification system excellent in ability to remove CO, NOx, and HC.

Carbon-based single metal atom or bimetallic, trimetallic, or multimetallic alloy transition metal-containing catalysts derived from exoelectrogen bacteria and their methods of making and using thereof are described. The method comprising the steps of: (a) preparing a solution medium comprising at least an electron donor and an electron acceptor comprised of one or more salts of a transition metal; (b) providing exoelectrogen bacterial cells and mixing the exoelectrogen bacterial cells into the solution medium of step (a); (c) incubating the solution medium of step (b); (d) isolating the exoelectrogen bacterial cells from the incubated solution medium of step (c); and (e) pyrolyzing the exoelectrogen bacterial cells resulting in formation of the catalyst. The electron donor can be formate, acetate, or hydrogen.

The invention provides a process for regenerating a catalyst used for the ring hydrogenation of an aromatic species, especially an aromatic ester, wherein a gas stream containing a particular amount of oxygen is used for the regeneration.

Disclosed are a catalyst for preparing a synthetic gas through dry reforming, a method preparing the catalyst, and a method using the catalyst for preparing the synthetic gas. The catalyst may include: a support including regularly distributed mesopores; metal nanoparticles supported on the support; and a metal oxide coating layer coated on a surface of the support.

Systems for treating wastewater containing organic nitrogen compounds are disclosed. The systems include a wet air oxidation unit having an oxidation zone, a catalytic zone, and a metal-based catalyst. Methods of treating wastewater containing organic nitrogen compounds are also disclosed. The methods include contacting the wastewater with an oxidant to produce a mixed liquor, contacting the mixed liquor with a metal-based catalyst to catalyze ammonia and produce a gas containing nitrogen and a liquid effluent containing nitrogen. Methods of retrofitting a wet air oxidation unit including providing a metal-based catalyst are also disclosed. Methods of facilitating treatment of wastewater in a wet air oxidation unit including providing a metal-based catalyst are also disclosed.

A photocatalytic device includes a substrate having a surface, and an array of conductive projections supported by the substrate and extending outward from the surface of the substrate. Each conductive projection of the array of conductive projections has a semiconductor composition. The semiconductor composition establishes a photochemical diode. The surface may be nonplanar such that subsets of the array of conductive projections are oriented at different angles.