The present invention relates to a catalyst which is a composite oxide including at least one element X selected from the group consisting of elements belonging to Groups 3 to 6 of the periodic table, and at least one element Z selected from the group consisting of elements belonging to Group 14 of the periodic table, wherein the catalyst has mesopores.

The present invention relates to a catalyst which is a composite oxide including at least one element X selected from the group consisting of elements belonging to Groups 3 to 6 of the periodic table, and at least one element Z selected from the group consisting of elements belonging to Group 14 of the periodic table, wherein the catalyst has mesopores.

A catalyst includes at least one element X selected from the group consisting of Groups 3 to 6 of the Periodic Table, and at least one element Z selected from the group consisting of Group 14 elements. At least one diffraction peak is observed in a low angle range of θ=6° or less in an X-ray diffraction profile observed using X-ray diffraction. The at least one diffraction peak has a ratio (I/H) of a peak intensity I to a half width at half maximum H of the diffraction peak of 5000 or more.

The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

A method for making a supported tantalum oxide catalyst precursor or catalyst with controlled Ta distribution and the resulting supported Ta catalyst. In an embodiment, the method comprises selecting a Ta-precursor with appropriate reactivity with the surface hydroxyls of the solid oxide support material to give a desired Ta distribution in the catalyst precursor or catalyst. In an embodiment the method comprises controlling the number of surface hydroxyls available on the support material to react with the Ta-precursor by thermal methods, such as calcination, to achieve the desired Ta distribution.

A method for making a supported tantalum oxide catalyst precursor or catalyst with controlled Ta distribution and the resulting supported Ta catalyst. In an embodiment, the method comprises selecting a Ta-precursor with appropriate reactivity with the surface hydroxyls of the solid oxide support material to give a desired Ta distribution in the catalyst precursor or catalyst. In an embodiment the method comprises controlling the number of surface hydroxyls available on the support material to react with the Ta-precursor by thermal methods, such as calcination, to achieve the desired Ta distribution.

A method of forming a bismuth-based catalyst can include mixing an inorganic alkali compound, a bismuth source compound, a transition metal precursor, and a reducing agent in an aqueous solution to form a bismuth precursor liquid. The bismuth precursor liquid can be hydrothermally reacted at a conversion temperature for a conversion time to produce the bismuth-based catalyst.

The invention concerns a catalyst comprising at least the element tantalum, and at least one mesoporous oxide matrix that has undergone an acid wash comprising at least 90% by weight of silica before washing, the mass of the element tantalum being in the range 0.1% to 30% of the mass of said mesoporous oxide matrix.

The invention concerns a catalyst comprising at least the element tantalum, and at least one mesoporous oxide matrix that has undergone an acid wash comprising at least 90% by weight of silica before washing, the mass of the element tantalum being in the range 0.1% to 30% of the mass of said mesoporous oxide matrix.