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.

A method for preparing a mixed-metal oxide catalyst comprising molybdenum, vanadium, at least one of niobium or tantalum, and at least one of tellurium or antimony and useful for the oxidative dehydrogenation of ethane to ethylene, the method comprising preparing a catalyst precursor, pressing the precursor into a dense pellet using a pressure of greater than about 5,000 psi, and annealing the pellet to form the mixed-metal oxide catalyst.

A method for preparing a mixed-metal oxide catalyst comprising molybdenum, vanadium, at least one of niobium or tantalum, and at least one of tellurium or antimony and useful for the oxidative dehydrogenation of ethane to ethylene, the method comprising preparing a catalyst precursor, pressing the precursor into a dense pellet using a pressure of greater than about 5,000 psi, and annealing the pellet to form the mixed-metal oxide catalyst.

The invention relates to a process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms, comprising contacting a first gas stream comprising oxygen and the alkane containing 2 to 6 carbon atoms and/or the alkene containing 2 to 6 carbon atoms with a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium; followed by contacting a second gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein the second gas stream comprises 0 to 25 vol. % of the alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.

The invention relates to a process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms, comprising contacting a first gas stream comprising oxygen and the alkane containing 2 to 6 carbon atoms and/or the alkene containing 2 to 6 carbon atoms with a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium; followed by contacting a second gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein the second gas stream comprises 0 to 25 vol. % of the alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.

The invention relates to a method for producing a mixed oxide material containing the elements molybdenum, vanadium, niobium and tellurium, comprising the following steps: a) producing a mixture from starting compounds containing molybdenum, vanadium, niobium and a tellurium-containing starting compound, present in the tellurium in the +4 oxidation state, b) hydrothermal treatment of the mixture from starting compounds at a temperature of between 100 C. to 300 C., in order to obtain a product suspension, c) separating off and drying the solid material from the product suspension obtained in step b), d) activating the solid material in inert gas in order to obtain the mixed oxide material. The invention is characterized in that the tellurium-containing starting compound has a particle size D.sub.90 of less than 100 m.

The invention relates to a method for producing a mixed oxide material containing the elements molybdenum, vanadium, niobium and tellurium, comprising the following steps: a) producing a mixture from starting compounds containing molybdenum, vanadium, niobium and a tellurium-containing starting compound, present in the tellurium in the +4 oxidation state, b) hydrothermal treatment of the mixture from starting compounds at a temperature of between 100 C. to 300 C., in order to obtain a product suspension, c) separating off and drying the solid material from the product suspension obtained in step b), d) activating the solid material in inert gas in order to obtain the mixed oxide material. The invention is characterized in that the tellurium-containing starting compound has a particle size D.sub.90 of less than 100 m.

A catalyst which is highly active in dehydrogenation reaction of an alkylaromatic hydrocarbon not only in high-temperature regions (e.g. 600 to 650 C.) as found in the inlet of a catalyst bed in an apparatus for the production of SM but also in low-temperature regions (e.g. under 600 C.) as found in the outlet of a catalyst bed in an apparatus for the production of SM, where the temperature decreases as a result of endothermic reaction; and a process for producing the catalyst; and a dehydrogenation process using the catalyst. The catalyst contains iron (Fe), potassium (K), and cerium (Ce), and at least one rare earth element other than cerium.

A catalyst which is highly active in dehydrogenation reaction of an alkylaromatic hydrocarbon not only in high-temperature regions (e.g. 600 to 650 C.) as found in the inlet of a catalyst bed in an apparatus for the production of SM but also in low-temperature regions (e.g. under 600 C.) as found in the outlet of a catalyst bed in an apparatus for the production of SM, where the temperature decreases as a result of endothermic reaction; and a process for producing the catalyst; and a dehydrogenation process using the catalyst. The catalyst contains iron (Fe), potassium (K), and cerium (Ce), and at least one rare earth element other than cerium.