An oxidation catalyst composition is provided, the composition including a plurality of platinum group metal particles having a multi-modal distribution of particle sizes. The plurality of platinum group metal particles includes a first population of platinum group metal particles having a range of particle sizes of from about 0.5 nm to about 3 nm, and a second population of platinum group metal particles having a range of particle sizes of from about 4 nm to about 15 nm. Methods for the preparation and use of the catalyst composition are also provided, as well as catalyst articles and emission gas treatment systems employing such catalyst articles. The catalyst exhibits enhanced stability with respect to oxidation performance after degreening and/or aging, as compared to conventional oxidation catalysts, in particular less loss of NOx oxidation performance.

A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m.sup.2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C., more preferably at least 1400° C., in particular at least 1450° C., to obtain the tableted alpha-alumina catalyst support. The invention moreover relates to a compacted body obtained by tableting a free-flowing feed mixture which comprises, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g, as determined, and a median pore diameter of at least 15 nm. The invention moreover relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on the tableted alpha-alumina catalyst support. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of the shaped catalyst body.

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.

Embodiments of catalyst systems and methods of synthesizing catalyst systems are provided. The catalyst system may include a core comprising a zeolite; and a shell comprising a microporous fibrous silica. The shell may be in direct contact with at least a majority of an outer surface of the core. The catalyst system may have a Si/Al molar ratio greater than 5. At least a portion of the shell may have a thickness of from 50 nanometers (nm) to 600 nm.

Provided are catalyst particles for treating vehicle exhaust gas, containing semiconductor nanoparticles supported by noble metals.

Disclosed are shaped dehydrogenation catalysts, methods for making the catalysts, and methods for dehydrogenating a hydrocarbon using the catalyst. A method for making the shaped dehydrogenation catalyst can include combining a group 13 metal precursor and a group 1 metal precursor with a catalyst support precursor to form a shapeable material, shaping the shapeable material to form a wet shaped material, drying the wet shaped material to form a dry shaped material, and calcining the dry shaped material to form the shaped dehydrogenation catalyst.

This disclosure relates to red mud compositions. This disclosure also relates to methods of making red mud compositions. This disclosure additionally relates to methods of using red mud compositions.

The present invention discloses a low-platinum catalyst based on nitride nanoparticles and a preparation method thereof. A component of an active metal of the catalyst directly clades on a surface of nitride particles or a surface of nitride particles loaded on a carbon support in an ultrathin atomic layer form. Preparation steps including: preparing a transition-metal ammonia complex first, nitriding the obtained ammonia complex solid under an atmosphere of ammonia gas to obtain nitride nanoparticles; loading the nitride nanoparticles on a surface of a working electrode, depositing an active component on a surface of the nitride nanoparticles by pulsed deposition, to obtain the low platinum loading catalyst using a nitride as a substrate. The catalyst may be used as an anode or a cathode catalyst of a low temperature fuel cell, has very high catalytic activity and stability, can greatly reduce a usage amount of a precious metal in the fuel cell, and greatly reduces a cost of the fuel cell. The present invention has important characteristics of being controllable in deposition amount, simple and convenient to operate, free of protection of inert atmosphere, and etc., and is suitable for large-scale industrial production.

The present disclosure relates to an FCC catalyst composition and a process for its preparation. The FCC catalyst composition comprises Y type zeolite, silicon oxide, alumina, at least one clay, at least one rare earth metal, and at least one metal oxide. The FCC catalyst composition of the present disclosure provides improved yields of high value gasoline such as propylene and LPG and reduces yields of low value hydrocarbons such as CSO and LCO.

Described herein are compositions and methods relating to molecular cerium-oxide nanoclusters. Described herein are methods of producing cerium-oxide nanoclusters. Described herein are cerium-oxide nanoclusters. Further described herein are cerium-oxide nanoclusters produced by methods as described herein. Methods as described herein can comprise providing a first cerium source, an organic acid, and a solvent; and mixing the cerium source and the organic acid in the presence of a solvent to create a reaction mixture at a temperature and a pressure for a period of time to create a composition of molecular cerium-oxide nanoclusters containing a plurality of molecular cerium-oxide nanoclusters.