Nanostellar, Inc.

Chevron Phillips Chemical Company LP

Shubin, Inc.

Wgch Technology Limited

Xianghong Hao

Ryan W Snell

Jifei Jia

Juan Cai

Jonathan W Woo

Mats Larsson

Gabriela Alvez-Manoli

Jian Wang

Geoffrey McCool

Brian Harrison

Cetin Kilic

Ligen Wang

Ramesh Sharma

Dietmar Wahl

Jangsuk Hyun

Scott G Morrison

Vincent D McGahee

Deepak Srivastava

Bulent Yavuz

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Aromatization processes using both fresh and regenerated catalysts, and related multi-reactor systems

A process for operating a reforming system by operating a reforming section containing a plurality of reactors, wherein each of the plurality of reactors containing a reforming catalyst capable of catalyzing the conversion of at least a portion of the hydrocarbons in a treated hydrocarbon stream into a reactor effluent comprising aromatic hydrocarbons, and operating a sulfur guard bed (SGB) to remove sulfur and sulfur-containing hydrocarbons from a hydrocarbon feed to provide the treated hydrocarbon stream, where the SGB contains at least a layer of a SGB catalyst comprising the same catalyst as the reforming catalyst, and where each reactor of the plurality of reactors within the reforming section may be operated at a higher operating temperature than an operating temperature of the SGB. A system for carrying out the process is also provided.

Use of Aromax&#xae; catalyst in sulfur converter absorber and advantages related thereto

Methods for producing supported catalysts containing a transition metal and a bound zeolite base are disclosed. These methods employ a step of washing the bound zeolite base in the presence of an alkali metal, prior to impregnating the bound zeolitic support with the transition metal. Alkali metals such as potassium and cesium may be used.

Aromatization catalyst preparation with alkali metal present during a washing step

An emission control catalyst for treating an engine exhaust includes non-precious metal group ('NPGM') mixed phase oxide catalyst having a mullite phase containing optionally in close contact with other metal oxides. The mixed phase catalyst may be included in one or more layers or zones of a multi-layered or multi-zoned emission control catalyst and optionally in combination with precious metal catalysts such as Pt, Pd and Au.

Mixed phase oxide catalysts

A supported palladium-gold catalyst is produced under mild conditions using a commonly available base, such as sodium hydroxide (NaOH) or sodium carbonate (NaCO). In this method, support materials and a base solution are mixed together and the temperature of the mixture is increased to a temperature above room temperature. Then, palladium salt and gold salt are added to the mixture while maintaining the pH of the mixture to be greater than 7.0 and keeping the mixture at a temperature above room temperature. This is followed by cooling the mixture while adding acetic acid to maintain the pH of the mixture to be within a desired pH range, filtering out the supported palladium-gold particles, washing with a pH buffer solution and calcining.

Palladium&#x2014;gold catalyst synthesis

An emission control catalyst includes copper-ceria to boost low temperature CO oxidation performance, generate exothermic heat during the process, and reduce HC and NOemissions. As a result, system performance is boosted at equal catalyst cost or maintained at a reduced catalyst cost. In one embodiment, an engine exhaust catalyst includes a first washcoat layer having at least one of a platinum-based catalyst, a palladium-based catalyst, and combinations thereof; and a second washcoat layer having copper-ceria.

Engine exhaust catalysts containing copper-ceria

Palladium-gold catalyst synthesis

A supported palladium-gold catalyst is produced under mild conditions using a commonly available base, such as sodium hydroxide (NaOH) or sodium carbonate (NaCO). In this method, support materials and a base solution are mixed together and the temperature of the mixture is increased to a temperature above room temperature. Then, palladium salt and gold salt are added to the mixture while maintaining the pH of the mixture to be greater than 7.0 and keeping the mixture at a temperature above room temperature. This is followed by filtering out the supported palladium-gold particles, washing with warm de-ionized water and calcining.

A sample preparation method for characterization of nanoparticles embedded in the supports of heterogeneous catalysts, with improved particle dispersion, is introduced. The supported catalyst is first ground or milled into fine powder. Then, the powder is mixed into an organic solvent, and an etchant is added to the solvent to digest the supports and release metallic nanoparticles. The resulting solution is then placed in an ultrasonic bath where ultrasonic waves are generated and applied to the solution. The ultrasonic waves suppress agglomeration of the particles and also break up those particle clusters resulting from agglomeration during the prior steps. Subsequently, a sample is extracted from the solution and prepared for analysis.

Dissolving metal particles from supported catalyst using ultrasonic energy, solvent and etchant

The catalytic efficiency of supported catalysts containing metal nanoparticles is strongly related to the chemical softness at the surfaces of such nanoparticles. Supported catalysts containing platinum nanoparticles having average surface softness values (expressed in scaled units ranging from 0 to 1) between 0.07198 and 0.09247 exhibit high catalytic efficiency. The catalytic efficiency of such platinum nanoparticles for CO oxidation, expressed as the turn-over frequency (TOF), was observed to be on or above 0.03062 s. The supported catalysts containing platinum nanoparticles with tighter average surface softness ranges exhibit even higher catalytic efficiencies. The TOF for CO oxidation of platinum nanoparticles having average surface softness values between 0.08031 and 0.08679 was observed to be on or above 0.06554 s.

Supported catalysts having platinum particles

The catalytic efficiency of supported catalysts containing metal nanoparticles is strongly related to the chemical softness at the surfaces of such nanoparticles. The chemical softness of a nanoparticle is obtained using results from Density Functional Theory modeling, an extended version of Embedded Atom Method modeling, and continuum modeling based on size and shape of the nanoparticle. A metal nanoparticle of a certain size and shape is first modeled using the extended EAM and EAM parameters that have been validated with results from DFT modeling, to obtain atomic energy densities at each atom location. The chemical softness value at each atom location is then calculated from the atomic energy densities and various parameters that are derived based on results from DFT modeling. The surface chemical softness value is derived from the local chemical softness values based on the geometry and atomistic structure of the metal nanoparticle.

Method of estimating chemical reactivity of nanoparticles

A method for producing highly dispersed catalysts is disclosed. The method includes contacting a support material with a solvent for a period of time, adding a metal salt to the solvent and support mixture, and then adding a reducing agent to the solution to reduce the metal salt to nanometer sized metal particles on the surface of the support. Excess solvent is used in the process, the volume of solvent being greater than two times the pore volume of the support.

Method for producing heterogeneous catalysts containing metal nanoparticles

Supported catalysts are produced with nanometer sized particles comprised of different metals dispersed throughout the catalyst support material. The supported catalysts reduce substantially or completely the amount of platinum that is required without sacrificing catalytic performance. In place of platinum, the supported catalysts employ palladium, silver, or copper, all of which costs significantly less than platinum.

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Sunnyvale, CA, United States of America

Xianghong Hao