The disclosure relates to a single-atom-based catalyst system with total-length control of single-atom catalytic sites. The single-atom-based catalyst system comprises at least one catalyst structure comprising a first assembly of a plurality of single-atom-catalyst superparticles. The single-atom-catalyst superparticles comprise a second assembly of a plurality of single-atom-catalyst nanoparticles. The single-atom-based catalyst system has controlled porosity and spatial distribution of active single-atom catalysts from the atomic scale to the macroscopic scale. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

The invention relates to a catalyst composition suitable for the dehydrogenation of paraffins having 2-8 carbon atoms comprising zinc oxide and titanium dioxide, optionally further comprising oxides of cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm), terbium (Tb), ytterbium (Yb), yttrium (Y), tungsten (W) and Zirconium (Zr) or mixtures thereof, wherein said catalyst composition is substantially free of chromium and platinum. The catalysts possess unique combinations of activity, selectivity, and stability. Methods for preparing improved dehydrogenation catalysts and a process for dehydrogenating paraffins having 2-8 carbon atoms, comprising contacting the mixed metal oxide catalyst with paraffins are also described. The catalyst may also be disposed on a porous support in an attrition-resistant form and used in a fluidized bed reactor.

The invention relates to a catalyst composition suitable for the dehydrogenation of paraffins having 2-8 carbon atoms comprising zinc oxide and titanium dioxide, optionally further comprising oxides of cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm), terbium (Tb), ytterbium (Yb), yttrium (Y), tungsten (W) and Zirconium (Zr) or mixtures thereof, wherein said catalyst composition is substantially free of chromium and platinum. The catalysts possess unique combinations of activity, selectivity, and stability. Methods for preparing improved dehydrogenation catalysts and a process for dehydrogenating paraffins having 2-8 carbon atoms, comprising contacting the mixed metal oxide catalyst with paraffins are also described. The catalyst may also be disposed on a porous support in an attrition-resistant form and used in a fluidized bed reactor.

A system for oxidative conversion of a mixed hydrocarbon feed stream to a product stream containing at least one olefin is provided. The system includes a plurality of reactors each capable of oxidatively dehydrogenating at least a portion of a hydrocarbon in the mixed hydrocarbon feed, and each reactor able to operate at different set of reaction conditions from other reactors in the plurality of reactors. All of the reactors use the same oxygen transfer agent to produce at least one olefin. In some embodiments, at least one reactor is optimized to oxidatively couple methane to produce ethylene, while other reactors are optimized to oxidatively dehydrogenate ethane to ethylene or to oxidatively dehydrogenate propane to ethylene and/or propylene. All of the reactors feed into a single regeneration unit for the oxygen transfer agent. A method of oxidatively converting the mixed hydrocarbon feed to an olefin is also provided.

There is provided a method for preparation of oxide support-nanoparticle composites, in which metal nanoparticles decorate with uniform size and distribution on the surface of an oxide support, and thus, high performance oxide support-nanoparticle composites that can be applied in the fields of heterogeneous catalysis can be provided.

Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogeneous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogeneous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

A burner using a high-temperature combustion catalyst is disclosed. The disclosed burner using a high-temperature combustion catalyst comprises: a mixing and dispensing unit for mixing and dispensing fuel gas and air, which are to be supplied; a combustion catalyst unit for generating heat by catalytically combusting with the fuel gas to be supplied from the mixing and dispensing unit; and a premixing chamber for preliminarily mixing a combustion gas which is to enter the combustion catalyst unit while connecting the mixing and dispensing unit and the combustion catalyst unit, wherein the combustion catalyst unit comprises: a front/rear-open housing having a chamber therein; perforated plates provided on the front and rear surfaces of the housing so as to allow the fuel gas to pass through from the rear of the housing to the front thereof; a pellet-type combustion catalyst filled inside of the chamber of the housing; and a heat source means for generating a heat source for the catalytic combustion of the combustion catalyst. The high-temperature combustion catalyst further comprises preparation by the steps of: preparing a metal precursor solution containing a transition metal nitrate, an alkaline earth metal nitrate, and aluminum nitrate; preparing a precipitation solution; preparing a mixture solution by mixing the metal precursor solution and the precipitation solution; increasing the temperature of the mixture solution to 90˜100° C. and maintaining the same for 10˜48 hours so as to cause precipitation; separating a precipitate slurry, which is formed by precipitation, from the mixture solution by filtering the same; washing the precipitate slurry; performing drying in order to remove water contained in the washed precipitate slurry; and performing firing at 1,000˜1,500° C. in order to remove water remaining in the dried precipitate slurry.

A burner using a high-temperature combustion catalyst is disclosed. The disclosed burner using a high-temperature combustion catalyst comprises: a mixing and dispensing unit for mixing and dispensing fuel gas and air, which are to be supplied; a combustion catalyst unit for generating heat by catalytically combusting with the fuel gas to be supplied from the mixing and dispensing unit; and a premixing chamber for preliminarily mixing a combustion gas which is to enter the combustion catalyst unit while connecting the mixing and dispensing unit and the combustion catalyst unit, wherein the combustion catalyst unit comprises: a front/rear-open housing having a chamber therein; perforated plates provided on the front and rear surfaces of the housing so as to allow the fuel gas to pass through from the rear of the housing to the front thereof; a pellet-type combustion catalyst filled inside of the chamber of the housing; and a heat source means for generating a heat source for the catalytic combustion of the combustion catalyst. The high-temperature combustion catalyst further comprises preparation by the steps of: preparing a metal precursor solution containing a transition metal nitrate, an alkaline earth metal nitrate, and aluminum nitrate; preparing a precipitation solution; preparing a mixture solution by mixing the metal precursor solution and the precipitation solution; increasing the temperature of the mixture solution to 90˜100° C. and maintaining the same for 10˜48 hours so as to cause precipitation; separating a precipitate slurry, which is formed by precipitation, from the mixture solution by filtering the same; washing the precipitate slurry; performing drying in order to remove water contained in the washed precipitate slurry; and performing firing at 1,000˜1,500° C. in order to remove water remaining in the dried precipitate slurry.

The present invention provides a process for preparing a catalyst, wherein said process comprises:—(i) preparing a mixture of one or more aromatic alcohol monomers and/or non-aromatic monomers, solvent, polymerization catalyst, crosslinking agent, suspension stabilizing agent and one or more metal salts, under conditions sufficient to produce polymeric beads doped with one or more metals or salts thereof; (ii) carbonizing, activating and then reducing the polymeric beads produced in step (i) to produce metal nanoparticles-doped porous carbon beads; (iii) subjecting the metal nanoparticles-doped porous carbon beads produced in step (ii) to chemical vapour deposition in the presence of a carbon source to produce metal nanoparticles-doped porous carbon beads comprising carbon nanofibers; and (iv) doping the metal nanoparticles-doped porous carbon beads comprising carbon nanofibers produced in step (iii) with an oxidant; catalyst prepared by said process; and a process for treating waste water from an industrial process for producing propylene oxide, which process comprises subjecting the waste water to a catalytic wet oxidation treatment in the presence of said catalyst.