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.

The present invention provides a catalyst including Mo, Bi, and Fe, wherein P/R is 0.10 or less, wherein P is a peak intensity at 2=22.90.2 and R is a peak intensity at 2=26.60.2, in X-ray diffraction analysis.

The present invention provides a catalyst including Mo, Bi, and Fe, wherein P/R is 0.10 or less, wherein P is a peak intensity at 2=22.90.2 and R is a peak intensity at 2=26.60.2, in X-ray diffraction analysis.

The present disclosure provides methods for fabricating catalysts for ammonia decomposition. The method may comprise (a) subjecting a catalyst support to one or more physical or chemical processes to optimize one or more pores, morphologies, and/or surface chemistry or property of the catalyst support; (b) depositing a composite support material on the catalyst support, wherein the composite support material comprises a morphology or surface chemistry or property; and (c) depositing one or more active metals on at least one of the composite support material and the catalyst support, wherein the one or more active metals comprise one or more nanoparticles configured to conform to the morphology of the composite support material and/or catalyst support material, thereby optimizing one or more active sites on the nanoparticles for ammonia processing.

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.

A method for producing an ammoxidation catalyst, comprising: a step of preparing a precursor slurry that is a precursor of the catalyst; a drying step of obtaining a dry particle from the precursor slurry; and a calcination step of calcining the dry particle, wherein the step of preparing the precursor slurry is a step of mixing a first solution or slurry having a first pH and a second solution or slurry to obtain a solution or slurry having a second pH after completion of mixing, a time during which a pH of a mixture passes through a particular range having an upper limit and a lower limit while the second solution or slurry is mixed is 1-70 seconds, the upper limit and the lower limit being designated as a third pH and a fourth pH respectively, and the third pH and the fourth pH are set between the first pH and the second pH.

A method for producing an ammoxidation catalyst, comprising: a step of preparing a precursor slurry that is a precursor of the catalyst; a drying step of obtaining a dry particle from the precursor slurry; and a calcination step of calcining the dry particle, wherein the step of preparing the precursor slurry is a step of mixing a first solution or slurry having a first pH and a second solution or slurry to obtain a solution or slurry having a second pH after completion of mixing, a time during which a pH of a mixture passes through a particular range having an upper limit and a lower limit while the second solution or slurry is mixed is 1-70 seconds, the upper limit and the lower limit being designated as a third pH and a fourth pH respectively, and the third pH and the fourth pH are set between the first pH and the second pH.

A process for producing unsaturated nitrile, using a fluidized bed reactor having an internal space having a catalyst capable of being fluidized therein, a feed opening to feed a starting material gas comprising hydrocarbon to the internal space, and a discharge port to discharge a reaction product gas from the internal space, the process comprising a reaction step of subjecting the hydrocarbon to a vapor phase catalytic ammoxidation reaction in the presence of the catalyst in the internal space to produce the corresponding unsaturated nitrile, wherein when in the internal space, a space where an existing amount of the catalyst per unit volume is 150 kg/m.sup.3 or more is defined as a dense zone and a space where an existing amount of the catalyst per unit volume is less than 150 kg/m.sup.3 is defined as a sparse zone in the reaction step, a gas residence time in the sparse zone is 5 to 50 sec.

A process for producing unsaturated nitrile, using a fluidized bed reactor having an internal space having a catalyst capable of being fluidized therein, a feed opening to feed a starting material gas comprising hydrocarbon to the internal space, and a discharge port to discharge a reaction product gas from the internal space, the process comprising a reaction step of subjecting the hydrocarbon to a vapor phase catalytic ammoxidation reaction in the presence of the catalyst in the internal space to produce the corresponding unsaturated nitrile, wherein when in the internal space, a space where an existing amount of the catalyst per unit volume is 150 kg/m.sup.3 or more is defined as a dense zone and a space where an existing amount of the catalyst per unit volume is less than 150 kg/m.sup.3 is defined as a sparse zone in the reaction step, a gas residence time in the sparse zone is 5 to 50 sec.