Disclosed is a method for preparing a carbon-supported platinum-transition metal alloy nanoparticle catalyst using a stabilizer. According to the method, the transition metal on the nanoparticle surface and the stabilizer are simultaneously removed by treatment with acetic acid. Therefore, the method enables the preparation of a carbon-supported platinum-transition metal alloy nanoparticle catalyst in a simple and environmentally friendly manner compared to conventional methods. The carbon-supported platinum-transition metal alloy nanoparticle catalyst can be applied as a high-performance, highly durable fuel cell catalyst.

Methods for preparing a catalyst system, include providing a catalytic substrate comprising a catalyst support having a surface with a plurality of metal catalytic nanoparticles bound thereto and physically mixing and/or electrostatically combining the catalytic substrate with a plurality of oxide coating nanoparticles to provide a coating of oxide coating nanoparticles on the surface of the catalytic nanoparticles. The metal catalytic nanoparticles can be one or more of ruthenium, rhodium, palladium, osmium, iridium, and platinum, rhenium, copper, silver, and gold. Physically combining can include combining via ball milling, blending, acoustic mixing, or theta composition, and the oxide coating nanoparticles can include one or more oxides of aluminum, cerium, zirconium, titanium, silicon, magnesium, zinc, barium, lanthanum, iron, strontium, and calcium. The catalyst support can include one or more oxides of aluminum, cerium, zirconium, titanium, silicon, magnesium, zinc, barium, iron, strontium, and calcium.

Disclosed are ruthenium-based catalyst systems, hafnium-based catalyst systems, and yttrium-based catalyst systems for use in ammonia decomposition. Catalyst systems include ruthenium, hafnium, and/or yttrium optionally in combination with one or more additional metals that can be catalytic or catalyst promoters. Hafnium-based and yttrium-based catalyst systems can be free of ruthenium. The catalyst systems also include a support material. Disclosed catalyst systems can decompose ammonia at relatively low temperatures and can provide an efficient and cost-effective route to utilization of ammonia as a carbon-free hydrogen storage and generation material.

Disclosed are ruthenium-based catalyst systems, hafnium-based catalyst systems, and yttrium-based catalyst systems for use in ammonia decomposition. Catalyst systems include ruthenium, hafnium, and/or yttrium optionally in combination with one or more additional metals that can be catalytic or catalyst promoters. Hafnium-based and yttrium-based catalyst systems can be free of ruthenium. The catalyst systems also include a support material. Disclosed catalyst systems can decompose ammonia at relatively low temperatures and can provide an efficient and cost-effective route to utilization of ammonia as a carbon-free hydrogen storage and generation material.

In general, disclosed herein are methods for forming hydrogen by use of an ammonia decomposition catalyst system. For instance, a method can include contacting a catalyst system with an ammonia source at a temperature of about 450? C. or lower. The catalyst systems can include a support material and a trimetallic catalyst component carried on the support material and within a reactor. Disclosed catalyst systems can decompose ammonia at relatively low temperatures and can provide an efficient and cost-effective route to utilization of ammonia as a carbon-free hydrogen storage and generation material.

In general, disclosed herein are methods for forming hydrogen by use of an ammonia decomposition catalyst system. For instance, a method can include contacting a catalyst system with an ammonia source at a temperature of about 450? C. or lower. The catalyst systems can include a support material and a trimetallic catalyst component carried on the support material and within a reactor. Disclosed catalyst systems can decompose ammonia at relatively low temperatures and can provide an efficient and cost-effective route to utilization of ammonia as a carbon-free hydrogen storage and generation material.

The present invention relates to diesel oxidation catalyst compositions and catalyst articles, wherein the compositions and articles include a plurality of platinum group nanoparticles substantially in fully reduced form, wherein the nanoparticles have an average particle size of about 1 to about 10 nm and at least about 90% of the nanoparticles have a particle size of +/ about 2 nm of the average particle size. Such compositions can further include a refractory metal oxide material, wherein the nanoparticles and refractory metal oxide material can be combined within the same coating on a substrate or can be applied sequentially on a substrate. The nanoparticles can advantageously be substantially free of halides, alkali metals, alkaline earth metals, sulfur compounds, and boron compounds. Methods of preparing and using such compositions and catalyst articles (e.g., for the treatment of diesel exhaust gas streams) are also provided herein.

The present invention relates, at least in part, to a process for making chlorotrifluoroethylene (CFO-1113) from 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a). In certain aspects, the process includes dehydrochlorinating 1,2-dichloro-1,1,2-trifluoroethane (HCFC-123a) in the presence of a catalyst selected from the group consisting of (i) one or more metal halides; (ii) one or more halogenated metal oxides; (iii) one or more zero-valent metals or metal alloys; (iv) combinations thereof.

A process for vapor-phase carbonylation of methanol to methyl formate, whereby a feed gas containing methanol, carbon monoxide, hydrogen and oxygen is passed through a reactor loaded with a supported nano-scaled platinum group metal heterogeneous catalyst to produce methyl formate by a vapor-phase carbonylation reaction, under reaction conditions with a space velocity of 500-5000 h.sup.1, a temperature of 50-150 C. and a pressure of 0.01-2 MPa. Supported nano-scaled platinum group metal heterogeneous catalysts are prepared via ultrasonic dispersion and calcination. Methyl formate is produced and isolated under relatively mild conditions.

A process for vapor-phase carbonylation of methanol to methyl formate, whereby a feed gas containing methanol, carbon monoxide, hydrogen and oxygen is passed through a reactor loaded with a supported nano-scaled platinum group metal heterogeneous catalyst to produce methyl formate by a vapor-phase carbonylation reaction, under reaction conditions with a space velocity of 500-5000 h.sup.1, a temperature of 50-150 C. and a pressure of 0.01-2 MPa. Supported nano-scaled platinum group metal heterogeneous catalysts are prepared via ultrasonic dispersion and calcination. Methyl formate is produced and isolated under relatively mild conditions.