A catalyst comprising Mo, Bi, and Fe, and satisfying, in an X-ray diffraction analysis, 0.10<P/R<0.18 and 0.06<Q/R<0.30 where P represents a peak intensity at 2θ=22.9±0.2°, Q represents a peak intensity at 2θ=28.1±0.1°, and R represents a peak intensity at 2θ=26.6±0.2°.

A catalyst comprising Mo, Bi, and Fe, and satisfying, in an X-ray diffraction analysis, 0.10<P/R<0.18 and 0.06<Q/R<0.30 where P represents a peak intensity at 2θ=22.9±0.2°, Q represents a peak intensity at 2θ=28.1±0.1°, and R represents a peak intensity at 2θ=26.6±0.2°.

A catalyst comprising molybdenum, bismuth, iron, and nickel, wherein a proportion of a surface concentration of the nickel to a bulk concentration of the nickel is 0.60 to 1.20.

A catalyst comprising molybdenum, bismuth, iron, and nickel, wherein a proportion of a surface concentration of the nickel to a bulk concentration of the nickel is 0.60 to 1.20.

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.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50° C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50° C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A method for producing a catalyst, including a slurry preparation step of preparing a slurry comprising a Mo compound, an Fe compound, a Bi compound, and an additive having a decomposition temperature of 500° C. or less; a drying step of drying the slurry to obtain a dried material; and a calcination step of calcining the dried material to obtain a calcined material, wherein the calcination step comprises a step of raising temperature of a calcination atmosphere to a predetermined temperature, and a temperature raising rate is 10° C./min or less at least at a temperature equal to or lower than the decomposition temperature of the additive.

A method for producing a catalyst, including a slurry preparation step of preparing a slurry comprising a Mo compound, an Fe compound, a Bi compound, and an additive having a decomposition temperature of 500° C. or less; a drying step of drying the slurry to obtain a dried material; and a calcination step of calcining the dried material to obtain a calcined material, wherein the calcination step comprises a step of raising temperature of a calcination atmosphere to a predetermined temperature, and a temperature raising rate is 10° C./min or less at least at a temperature equal to or lower than the decomposition temperature of the additive.

The oxidative coupling of methane (OCM) and the oxidative dehydrogenation (ODH) of ethane and higher hydrocarbons is described using SO.sub.3 and sulfate, sulfite, bisulfite and metabifulfite salts as oxygen transfer agents in the presence of one or more elements selected from Groups 3 to 14 of the periodic table, optionally further in the presence of alkali or alkaline salts and/or sulfur-containing compounds.