A catalyst for oxidative dehydrogenation (ODH) of ethane with an empirical formula Mo—V—Te—Nb—Pd—O produced using a process comprising impregnation of the Pd component on the surface of the catalyst following a calcination step using a Pd compound free of halogens. The resulting catalyst can be used in both diluted and undiluted ODH processes and shows higher than expected activity without any loss of selectivity.

The invention relates to a catalyst comprising a support based on alumina or silica or silica-alumina, at least one group VIII element, at least one group VIB element and at least one organic compound of formula (I) ##STR00001##
in which R.sub.1 is a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, R.sub.2 and R.sub.3 are chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, X is chosen from an oxygen atom or a sulfur atom except when R.sub.2 and R.sub.3 represent a hydrogen atom, in which case X is an oxygen atom, Y is chosen from a hydrogen atom, a hydrocarbon-based radical comprising from 1 to 12 carbon atoms or a unit —C(O)R.sub.4, R.sub.4 being chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms.

The invention relates to a catalyst comprising a support based on alumina or silica or silica-alumina, at least one group VIII element, at least one group VIB element and at least one organic compound of formula (I) ##STR00001##
in which R.sub.1 is a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, R.sub.2 and R.sub.3 are chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms, X is chosen from an oxygen atom or a sulfur atom except when R.sub.2 and R.sub.3 represent a hydrogen atom, in which case X is an oxygen atom, Y is chosen from a hydrogen atom, a hydrocarbon-based radical comprising from 1 to 12 carbon atoms or a unit —C(O)R.sub.4, R.sub.4 being chosen from a hydrogen atom and a hydrocarbon-based radical comprising from 1 to 12 carbon atoms.

A method includes supplying a gas containing acrolein to a fixed bed reactor including a reaction tube to produce acrylic acid by vapor phase catalytic oxidation of acrolein. The reaction tube is packed with catalysts having different activities in such a way that catalyst layers are formed in a tube axis direction. A catalyst X having the highest activity among the catalysts contained in all the catalyst layers is placed in the whole or a part of a section up to 30% of a length of all the catalyst layers from a rearmost portion on a gas outlet side toward a gas inlet side. A catalytically active component x in the catalyst X has Mo, V, and optionally Cu. When Cu is included, its amount is 0.8 mol or less per 12 mol of Mo. A specific surface area of the catalytically active component x is 15-40 m.sup.2/g.

A method includes supplying a gas containing acrolein to a fixed bed reactor including a reaction tube to produce acrylic acid by vapor phase catalytic oxidation of acrolein. The reaction tube is packed with catalysts having different activities in such a way that catalyst layers are formed in a tube axis direction. A catalyst X having the highest activity among the catalysts contained in all the catalyst layers is placed in the whole or a part of a section up to 30% of a length of all the catalyst layers from a rearmost portion on a gas outlet side toward a gas inlet side. A catalytically active component x in the catalyst X has Mo, V, and optionally Cu. When Cu is included, its amount is 0.8 mol or less per 12 mol of Mo. A specific surface area of the catalytically active component x is 15-40 m.sup.2/g.

Systems and methods for producing an isomerization product. One or more isomerization reactors comprising a catalyst may be used to process an isomerization feedstock comprising a primary n-paraffin reactant and hydrogen gas, and the isomerization reactor may be operated at a pressure parameter at which the partial pressure of the primary n-paraffin is within about 70% to about 130% of its equilibrium vapor pressure to isomerize the primary n-paraffin reactant.

There is provided an ammoxidation catalyst for propylene having a structure in which molybdenum (Mo) oxide is supported first, and an oxide of heterogeneous metals including bismuth (Bi) is supported later. Related methods of making and using the catalyst are also provided.

There is provided an ammoxidation catalyst for propylene having a structure in which molybdenum (Mo) oxide is supported first, and an oxide of heterogeneous metals including bismuth (Bi) is supported later. Related methods of making and using the catalyst are also provided.

Provided is a catalyst for manufacturing multi-wall carbon nanotubes, the catalyst including metal components according to <Equation> Ma:Mb=x:y, and having a hollow structure with a thickness of 0.5-10 μm. In the above equation, Ma represents at least two metals selected from Fe, Ni, Co, Mn, Cr, Mo, V, W, Sn, and Cu; Mb represents at least one metal selected from Mg, Al, Si, and Zr; x and y each represent the molar ratio of Ma and Mb; and x+y=10, 2.0≤x≤7.5, and 2.5≤y≤8.0.

Provided is a catalyst for manufacturing multi-wall carbon nanotubes, the catalyst including metal components according to <Equation> Ma:Mb=x:y, and having a hollow structure with a thickness of 0.5-10 μm. In the above equation, Ma represents at least two metals selected from Fe, Ni, Co, Mn, Cr, Mo, V, W, Sn, and Cu; Mb represents at least one metal selected from Mg, Al, Si, and Zr; x and y each represent the molar ratio of Ma and Mb; and x+y=10, 2.0≤x≤7.5, and 2.5≤y≤8.0.